johna's blog

Amstrad NC100 Notebook Computer Fuse Replacement

2026-05-28T12:00:00+10:00

I recently acquired a faulty Amstrad NC100 "Notebook Computer" from around 1992.

These were designed to be a simple to use computer for people who didn't know how to use computers. It has a built-in word processor, organiser, calculator and BASIC programming language. They run off AA batteries or a 6 volt DC power supply, and use a CR2032 lithium battery to store the contents of memory as there is no other form of storage.

Mine came complete with the original power supply, carry case and user's manual but wouldn't power on.

I did a little research and the common cause is simply a blown fuse. These use a less-common negative-tip power supply and will blow the fuse if the wrong power supply is connected.

Unfortunately the fuse is a surface mount device soldered to the underside of the main circuit board.

Although the circuit board label for the fuse is 0.8A (F301is the location), mine was fitted with one labelled "20" – which means 2.0A – and looked to be the original. My guess is that blown fuses were a common issue for Amstrad and they may have increased the value during production in hopes of reducing returns.

Sure enough, mine did have a blown fuse and I replaced it with a piece of wire to temporarily test it which is perfectly safe as long as you use a good power supply of the right type.

If you need to obtain a replacement fuse the size is 1210 and they are of a non-resetting type. I found this one on eBay and it appears to be a perfect match.

There are plenty of good instructions on how to disassemble this model, including YouTube videos, so this post is just to recommend which replacement fuse to use.

Sharp VC-793X VHS video recorder

2026-05-24T12:00:00+10:00

This Sharp video recorder comes from what I think is the best era of VHS, before the days of the modern units where all of the controls were on the remote.

It features four heads and HI-FI stereo, and it has a colourful display plus dual LED audio level meters, and a headphone socket with volume control.

There is a door covering extra controls at the front and a small covered panel at the top for some tuning controls.

At the rear there is AV in and out, although the video uses BNC connectors.

I'm not sure when these were available but suspect it to be around the late 1980s.

This one, probably around 35 years old, was making a high pitched noise when turned on and unable to eject the tape inside.

The swinging gear was not moving properly and unable to spin the tape. The sliding mechanism that controls the brake was also not moving feely which was causing the tape to bunch up.

All it needed was a bit of exercising and some lubrication and it came to life, although there was no picture or sound until the heads were cleaned.

A brief and incomplete history of clock radios

2026-03-27T12:00:00+10:00

These days, most people wake up to an alarm on their mobile phone, but back in the 1970s to 1990s most people had a clock radio beside their bed to help start their day.

The earliest clock radios had an analogue clock or those fantastic – but not so silent – flip numbers, and you could wake to the sound of an annoying buzzer or choose to wake to the sound of the radio.

Over time, alarms were improved with dual alarms for spouses that wake up at different times, and even separate alarms for weekdays and weekends.

Some manufacturers added extra features beyond just an alarm clock and radio. Some had a lamp or small night light. Some had a cassette player or recorder. Some embraced stereo with multiple speakers.

There were even models fitted with a small black and white television, or later a colour TV.

The addition of a telephone (one with a cord) was another common feature.

Clock radios are kind of still a thing today, although they are sometimes just a clock with a wireless charger for a mobile phone, or a clock with digital radio.

The clock radio pictured above is the very stylish Ross Wake-o-matic model 5500 from the 1970s. [eBay USA Listing]

Following are some note worthy clock radios from last century.

This Panasonic RC-6030 is an example of early clock radios with flip numbers and the most basic of features. [eBay USA Listing]

This is the Soundesign 3834 that I had back in the 1980s (see post). It had an usual design and the cassette recorder allowed you to record a message and leave a flashing message light so your housemates could play it back. So much better than leaving a paper note, right?

Soundesign must be the most prolific manufacturer of clock radios. Here is a model with cassette recorder and one with big stereo speakers [eBay USA listing].

Look at this amazing Philips P55 (CC 908), with a tiny B&W television. [eBay Australia listing

The Soundesign 7554 was an early clock radio with a telephone. [eBay USA listing]

This Soundesign Home Care had an unusual feature. It has an air purifier and ioniser built-in. [eBay USA Listing]

Images sourced from eBay listings. Please contact me if you do not want your image used.

Electronics in the 1980s were the best

2026-03-01T12:00:00+10:00

Electronics in the 1980s were the best. It was all about lots of switches and lots of lights.

Video Cassette Recorder (VCR)

The 1980s were the decade where VCRs took off.

Before this, you had to watch what was on television at the time it was on television. No watching what you wanted, when you wanted. No recording something to watch later. No buying or borrowing movies and definitely no streaming.

My family's first VCR was an Akai around 1980, and I have always admired the distinctive look of this brand's models.

Early models had the tape going into the top of the unit but it didn't take long for front-loading to become the norm. By the end of the 1980s you could get a stereo units and some had editing functions like my Sony SLV-757.

Hi-Fi Systems

In contrast to modern audio equipment, 1980s systems were almost a piece of furniture on their own.

Although some systems were just a single box with speakers, the best systems were made up of components. You would have an amplifier, an AM/FM tuner, a cassette or double-cassette recorder, and a record player.

A graphic equaliser was a very desirable feature, preferably with a spectrum analyser to visualise your music.

Car Audio

Although many car radios were just simple radio and sometimes cassette players, big stereos were popular.

One of the most revered systems was from Fujitsu Ten, which almost resembled a home component system.

Digital Watches

Although digital watches were available prior to the 1980s, the black plastic digital watch became very popular in the 1980s.

Common features were one or multiple alarms, hourly chime, stopwatch, countdown timer but the ones that was most interest in were calculator watches.

Clock Radios

Back in the 1980s we could choose to wake up to a noisy alarm or the the sound of a radio broadcast.

Clock radios might have peaked in the 1970s but were still popular in the 1980s. There's not much that can change with a clock radio other than styling, although some did integrate extras like a cassette recorder, a (corded) telephone or even a television.

Here is a picture of my Soundesign clock radio that I had as a child.

Games consoles

Although simple game consoles were becoming popular in the 1970s, by the 1980s some lucky families had something like an Atari 2600 or an Intellivision. The 1980s was a peak time for gaming consoles. They seemed to fizzle out with the rising popularity of home computers in the 1980s, but then they rose again during the 1990s and 2000s.

Computers

In the 1980s we weren't limited to just PC (or Linux) and Mac, although these systems all started in this decade. The home computer industry was just getting started and there were many manufacturers producing their own systems, most incompatible with everything else available. Many came and went quickly, never to be heard of again.

Home computers were, of course, simpler, and most booted into the BASIC programming language which resulted in many people learning to write their own software. It was also extremely popular for magazines to feature program listings -- mostly games -- that you could type in, which would usually take hours and involve finding and fixing many errors due to misreading or mistyping.

Here in Australia, Commodore was one of the most popular brands, particularly the C64 and then later in the 1980s, the Amiga.

Olivetti D2200 Electronic Notebook

2026-01-24T12:00:00+10:00

The Olivetti D2200 is a small personal organiser/PDA from around 1991.

It has two menus to access the organiser and calculator features, and a third menu for settings.

Data:

• Telephone Mode
• Business Card
• Memo Mode
• Schedule Mode
• Calendar
• Home Time
• World Time
• Anniversary Date

Calc:

• Calculator
• Replay Calculator
• Checkbook Record
• Project Planner
• Metric Conversion
• Currency Exchanger
• Size Conversion
• Expense Report

Func:

• Secret Code Set
• Communication
• User Dictionary
• Memory Collection
• Memory Check
• Key Tone
• Auto Power Off Period
• Auto Demo

The D2200 is powered by two AAA batteries and has a CR2016 3V battery for backup during battery changes. The dimensions are 15.5 cm wide, 8.5 cm deep, and 2 cm high (approximately).

How I used to create complex forms in dBase IV

2026-01-18T12:00:00+10:00

dBASE has methods to easily create data-entry forms but often I would want something more advanced. For example, I might want to allow the user to select a value for a field from a list of search for a value in a popup, or I might want to load data when a field is filled based on the data entered, or I might want the user to be able to press a function key to view some related information such as customer history.

Although some of this is possible using regular dBASE forms, I came up with my own way of creating forms where each field was handled individually.

This allowed me to display information only pertinent to the current field, such as press F1 to look up a value.

It also allowed me to do an action when a field was entered such as show a popup where the user could search or select for a value.

It also allowed me to skip fields that weren't needed based on the value of another field.

To accomplish this, I first need to initialise some settings for the Escape and F10 keys, and then define memory variables to store the forms values temporarily until save.

SET FUNCTION F10 TO CHR(28)
SET ESCAPE ON

tmp_acc = SPACE(6)
tmp_name = SPACE(30)
tmp_add = SPACE(30)
tmp_city = SPACE(30)
tmp_state = SPACE(3)
tmp_pcode = SPACE(5)

I also need some memory variables to store the state of the form and the current field.

tmp_dirty = .F.
frm_field = 1

We need some procedures to get and say field values. I originally used the same procedure for this and then followed it with either READ or CLEAR GETS depending on whether entering or displaying the form value, but having two procedures adds the option to do different things depending on whether getting or saying, such as showing something when in get mode and then clearing it when finished editing.

PROCEDURE get_field
PARAMETERS fieldno
    DO CASE
        CASE fieldno = 1
            @ 3, 15 GET tmp_acc PICTURE "XXXXXX"
            @ 24, 0 SAY "Lookup"
        CASE fieldno = 2
            @ 4, 15 GET tmp_name PICTURE "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
        CASE fieldno = 3
            @ 5, 15 GET tmp_add PICTURE "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
        CASE fieldno = 4
            @ 6, 15 GET tmp_city PICTURE "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
        CASE fieldno = 5
            @ 7, 15 GET tmp_state PICTURE "XXX"
        CASE fieldno = 6
            @ 8, 15 GET tmp_pcode PICTURE "XXXXX"
    ENDCASE
RETURN

PROCEDURE say_field
PARAMETERS fieldno
    DO CASE
        CASE fieldno = 1
            @ 3, 15 SAY tmp_acc PICTURE "XXXXXX"
            @ 24, 0 SAY "      "
        CASE fieldno = 2
            @ 4, 15 SAY tmp_name PICTURE "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
        CASE fieldno = 3
            @ 5, 15 SAY tmp_add PICTURE "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
        CASE fieldno = 4
            @ 6, 15 SAY tmp_city PICTURE "XXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
        CASE fieldno = 5
            @ 7, 15 SAY tmp_state PICTURE "XXX"
        CASE fieldno = 6
            @ 8, 15 SAY tmp_pcode PICTURE "XXXXX"
    ENDCASE
RETURN

Next step is to display the form and the current values. In this example I call the say procedure for each field, but it would make more sense to do this in a loop if you had more fields than this.

@ 0, 0 CLEAR TO 24, 79
@ 0, 35 SAY "Sample Form"

@ 3, 0 SAY "Account:"
DO say_field WITH 1
@ 4, 0 SAY "Name:"
DO say_field WITH 2
@ 5, 0 SAY "Address:"
DO say_field WITH 3
@ 6, 0 SAY "City:"
DO say_field WITH 4
@ 7, 0 SAY "State:"
DO say_field WITH 5
@ 8, 0 SAY "Postcode:"
DO say_field WITH 6

@ 23, 0 SAY "F1      F2      F3      F4      F5      F6      F7      F8      F9      F10    "
@ 24, 72 SAY "Save"

Now we need the program loop.

DO WHILE frm_field # 0

    *** Pre- field, used to skip conditional fields
    DO CASE
        *CASE frm_field = 

    ENDCASE

    *** Get field
    DO get_field WITH frm_field

    *** Read the field
    READ
    frm_rkey = IIF(READKEY() > 256, READKEY() - 256, READKEY())
    frm_fdirty = READKEY() >= 256
    tmp_dirty = IIF(frm_fdirty, .T., tmp_dirty)

    *** Show the field
    DO say_field WITH frm_field

    frm_lfield = frm_field  && Remember the field just read

    *** Handle key used to exit read mode
    DO CASE
        CASE frm_rkey = 6  && Page up
        CASE frm_rkey = 7  && Page down
        CASE frm_rkey = 14  && Ctrl+end
            *** Go to end of form
            frm_field = 6
        CASE frm_rkey = 33  && Ctrl_home
            *** Go to start of form
            frm_field = 1
        CASE frm_rkey = 12  && Escape
            *** Handle exit without save
            IF tmp_dirty = .F.
                *** Exit form, no save
                RETURN
            ENDIF
            *** Ask the user first
            @ 16, 0 SAY "Are you sure (Y/N)?"
            lkey = 0
            DO WHILE UPPER(CHR(lkey)) # "Y" .AND. UPPER(CHR(lkey)) # "N" .AND. lkey # 27
                lkey = INKEY()
            ENDDO
            IF UPPER(CHR(lkey)) = "Y"
                RETURN
            ENDIF
            @ 16, 0 CLEAR TO 16, 79
        CASE frm_rkey = 36 .AND. LASTKEY() = -9  && F10 key
            *** Exit loop to save
            frm_field = 0
        CASE frm_field = 1 .AND. frm_rkey = 36 .AND. LASTKEY() = 28  && F1 key on account field
            *** TODO: Show a list
            acc_val = acc_select()
            DO CASE
                CASE acc_val = 1
                    tmp_acc = "CS    "
                    frm_fdirty = .T.
                CASE acc_val = 2
                    tmp_acc = "SMITH "
                    frm_fdirty = .T.
            ENDCASE
        CASE frm_rkey = 4  && Cursor up / previous field
            IF frm_field > 1
                frm_field = frm_field - 1
            ELSE
                @ 0, 0 SAY CHR(7)
            ENDIF
        CASE frm_rkey = 5 .OR. frm_rkey = 15 .OR. frm_rkey = 16  && Cursor down / enter / next field
            IF frm_field < 6
                frm_field = frm_field + 1
            ELSE
                @ 0, 0 SAY CHR(7)
            ENDIF
        OTHERWISE
            *** Unsupported exit key
            @ 0, 0 SAY CHR(7)
    ENDCASE

    *** Handle post-entry of specific fields
    DO CASE
        CASE frm_lfield = 1 .AND. frm_fdirty = .T.
            *** Account field changed
            DO CASE
                CASE tmp_acc = "CS"
                    tmp_name = "CASH SALES                    "
                    tmp_add = SPACE(30)
                    tmp_city = SPACE(30)
                    tmp_state = SPACE(3)
                    tmp_pcode = SPACE(5)
                CASE tmp_acc = "SMITH"
                    tmp_name = "JOHN SMITH                    "
                    tmp_add = "1 SMITH STREET                "
                    tmp_city = "SPRINGWOOD                     "
                    tmp_state = "NSW"
                    tmp_pcode = "2056 "
                OTHERWISE
                    tmp_acc = SPACE(6)
                    tmp_name = SPACE(30)
                    tmp_add = SPACE(30)
                    tmp_city = SPACE(30)
                    tmp_state = SPACE(3)
                    tmp_pcode = SPACE(5)
            ENDCASE
            *** Redisplay customer information
            DO say_field WITH 1
            DO say_field WITH 2
            DO say_field WITH 3
            DO say_field WITH 4
            DO say_field WITH 5
            DO say_field WITH 6
            DO say_field WITH 7
    ENDCASE
ENDDO

*** If execution gets to here then the user pressed save
RETURN

This first thing in the loop is an optional DO CASE that is useful for skipping conditional fields.

Next we call the get function and wait for user input and then store the key used to exit, and track whether there was a change to the value.

We then call the say function and store the current field as it may change, but we may need to reset, such as if an invalid value was entered.

Next we have a DO CASE to handle key presses. We need to handle moving forward and backward, as well as escape to exit the form, and in this case F10 to save the form. We also need to handle function key presses in specific fields.

Finally we have a DO CASE to handle form input. In this example we look up a customer based on an account number entered. Obviously in an actual application this wouldn't just be hard-coded like in the example, but look up the customer in a database table.

After the main loop, if the loop was EXITed then this means the user pressed save, so we take care of saving the memory variables to the database.

For my example I also need a function to select a customer. Again, this is just a simple example and would normally get data from the database.

FUNCTION acc_select
    acc_bar = 0
    DEFINE POPUP acc_popup FROM 4, 15 to 8, 35
    DEFINE BAR 1 OF acc_popup PROMPT "CS    "
    DEFINE BAR 2 OF acc_popup PROMPT "SMITH "
    ON SELECTION POPUP acc_popup DO acc_sel
    ACTIVATE POPUP acc_popup
    acc_bar = BAR()
    DEACTIVATE POPUP
    RELEASE POPUP acc_popup
RETURN acc_bar

PROCEDURE acc_sel
    DEACTIVATE POPUP
RETURN

Much of this also works with earlier versions of dBASE, except I couldn't find a way to use any of the function keys except F1.

The forms I created back in the 1990s were quite a bit more complex that this example but used the same techniques. I also created some more complex forms like an invoice form which included a paginated list of invoice items. I will cover these type of forms in a later post.

I originally came up with this type of form on my own back in the early 1990s, but I've recently came across a book on the Internet Archive that uses a similar technique, except the form definition is stored in a database. The book is dBASE IV Power Tools by Malcolm C. Rubel, from 1989.

Another pointless project - this time for MS-DOS - and how good is Claude?

2025-12-21T12:00:00+10:00

I've been looking at old MS-DOS applications and started thinking about what would have been a useful application for MS-DOS, with all the knowledge we have now.

The only thing I could think of was how MS-DOS could have been made easier to select files and folders and launch applications.

I know there were plenty of GUI and TUI applications that made it easy to manipulate files, but I think it might have been nice if the MS-DOS command line had autocomplete to help you out.

Instead of having to do lots of CD and DIR and having to know a file path and name before you could run a command, imagine being able to start typing COPY and then you would be presented with the first match in the current folder and then use the arrow up and down keys to select a file or folder.

Or how about being able to launch an executable or batch file just by typing the name, or having a list of file extensions and associated applications so you could open the file in the application by typing or selecting the filename.

Maybe there was something like this for MS-DOS that I never discovered, or maybe this exists now in Windows or Linux? Let me know because I don't know.

Anyway, I thought I might mock up a simple application to do this "for fun", and I looked at what language I could do this in without too much effort. QuickBasic 4.5? Doesn't seem to support getting a list of files very well (PDS 7.1 looks to do it, though). Turbo Pascal? Seemed to do what I needed but I'd never used Pascal before and probably not the most useful skill to learn in 2025. C? I've done plenty in C# but nothing in C for a couple of decades.

While I was asking AI for advice on which programming language to use, I thought maybe I should just get AI to do the whole job. Things have changed for me in 2025 and it's hard to put a few hours work into something when you can just instruct someone (oops, something) else to do it and then tell them what they got wrong.

I gave Gemini a go and it did pretty good for a proof-of-concept, but then I got greedy and wanted more, so I switched to Claude (Sonnet 4.5) and after some detailed instructions, and then many fixes and tweaks, I got a fully-functional system that seems almost production ready.

I am once again amazed at what AI can do. I didn't have high expectations as I thought developing for MS-DOS would not be possible (having once failed when I asked for some Commodore 64 BASIC work), but Claude once again proved itself as the best programming AI (to me, at least, and I also tried ChatGPT).

Claude called the application "Enhanced Command Prompt v1.0" but named the files "CMDPLUS", so I went with all of that.

After you start the application you are greeted with some introductory text and then what looks like a normal command prompt.

You type a character and autocomplete will kick in and suggest any matching known command. You can either keep typing, press up or down to cycle through any matches, or press tab to accept the current suggestion. The enter key will also accept any current suggestion and also execute the command.

Some commands accept a file path or file name as a parameter and if you start typing after the command name you will get autocomplete for paths and file names. Commands like copy will also take a second file.

Any parameters starting with a forward slash or hyphen will be treated as such. No autocomplete is available for these, although might be a nice feature.

I wasn't sure how best to distinguish between a command and starting an executable file or batch file so I went Linux-style so if you start typing with a path character like a drive specifier, back slash or a full stop or two followed by a back slash then you will be able to select a file to execute. If the file's extension is on the list of known extensions then the corresponding application will be started with the file path/name as the parameter.

Autocomplete can be cancelled by pressing the escape key, if needed.

Like DOSKEY MS-DOS 5+, a command history is available, so you can press cursor up and down to cycle through previous commands.

I was also thinking it might be handy to know the number of files affects when pattern matching characters are used when deleting, copying, etc, so Claude added a confirmation message when you use these commands and pattern matching characters with the number of files matched.

Most options are managed in a configuration file called "CMDPLUS.CFG", although it is optional.

One feature I thought would be very useful was the ability to record past screen pages so you could use page up and down to move around the last few pages. I didn't have much luck with this but will try again in a future post.

Download CMDPLUS.ZIP, a compressed file containing C++ source, executable and sample configuration file.

Update: So it turns out back as far as the 1990s there were applications that did all this and more. There are some good examples on this page. Even Windows command prompt has a form of autocomplete that I had never known about until now.

Commodore Computers stereo system from the 1980s

2025-10-23T12:00:00+10:00

Did you know that there was a Commodore-badged stereo system in the 1980s?

These were not actually readily available for purchase, but came as part of a package with the Amiga 500 (from memory). Most likely these were only on offer in the Australian market, but I could be wrong.

When I was working for a commodore retailer, we immediately split these from the bundles and sold them separately for $299 (again, from memory). Many of the staff bought them including myself. I had mine up until somewhere around 2010 when I sold it on eBay for probably next to nothing.

Commodore didn't actually manufacture these, of course. We worked out what record needle they used at some point and might have been able to infer the manufacturer based on that, but I no longer remember.

These systems featured an AM (mono)/FM (stereo) tuner, an amplifier with surround sound, auxiliary input, five band graphic equaliser, two-speed turntable, and a double cassette player/recorder.

Unfortunately the only photo I have is not very clear and I haven't been able to find any other photos online so I can't make out all of the features but I think the cassette allowed dubbing in both normal and high speed. It also had synchro dubbing (recording starts automatically when the player is started) and continuously play (not sure what this does - maybe when one cassette stops the other one starts).

I used my Commodore stereo a lot and it moved houses with me several times. When CDs became popular I connected up a CD player to it. I recall my only disappointment with it was that they level meter didn't really show any action unless the volume was turned up very high. In the 1980s we liked flashing lights and I wanted to see more of them. Turning the surround sound button didn't make much difference, if I remember correctly.

I remember that Commodore Australia bundled some other unusual items with Amigas around this time. I wish I could remember what else there was. Leave me a comment if you remember any other interesting bundles.

Update: I found a few old advertisements that mentioned this system. In January 1989 it was available for A$399 or A$1,399 as part of the Amiga 500 Mega Pack which included an A500, 1MB RAM and the Textcraft word processor (or $1,199 without the stereo). By February 1989 it had been reduced to $299.

Online emulators for vintage/retro computers

2025-08-06T12:00:00+10:00

Have you ever wanted to see what it was like to use one of the first personal computers or play some early video games?

Or maybe you are old enough to have used personal computers and games consoles in the 1970s and 1980s and want to relive old times?

Thanks to the efforts of some very clever people, and the power of modern hardware, there are emulators available for almost every vintage computer.

Although many emulators can be installed and run on your own modern computer, the focus of this post is online emulators. These require no effort and no skills to set up, you can just go to a web site and immediately experience an original personal computer or play a classic game.

You can play games on an Atari 2600, one of the early successful games consoles. When I was in primary school, my friend had one of these and I remember playing Asteroids and Pacman.

The Commodore 64 is the top-selling personal computer of all time. Like many computers in the 1980s, they boot immediately into BASIC. There were other popular systems at the time, such as the Amstrad CPC and ZX Spectrum.

Here in Australia, the Microbee was very popular in schools.

Maybe you would like to see some of the early graphic user interfaces like the Xerox Alto, Apple Lisa, Macintosh or the early days of Windows?

You could try out or relive the 32-bit personal computers that were introduced around the second half of the 1980s like the Commodore Amiga, Atari ST and Acorn Archimedes.

You can even find emulators for more modern PC's and Apple Macs, and there is one for the Commander X16, a modern retro-inspired computer.

Here's a list of online emulators that I have found:

Acorn
- Archimedes
  - https://archi.medes.live/
  - https://www.compumuseum.com/emularity.html?machine=aa310
- Electron
  - https://elkjs.azurewebsites.net/
  - https://www.compumuseum.com/player.html?machine=acornelectron
Amstrad
- CPC
  - https://retroshowcase.gr/cpcbox-master/
  - https://www.compumuseum.com/tinyemu.html?type=cpc464
Apple
- II
  - https://www.compumuseum.com/player.html?machine=apple2
- IIe
  - https://www.compumuseum.com/player.html?machine=apple2e
- IIGS
  - https://www.compumuseum.com/emularity.html?machine=apple2gs
- II Plus
  - https://www.compumuseum.com/emularity.html?machine=apple2p
- Macintosh
- Macintosh II
  - https://www.compumuseum.com/emularity.html?machine=maciichs
  - https://www.compumuseum.com/emularity.html?machine=macii
- Macintosh Plus
  - https://www.compumuseum.com/emularity.html?machine=macplus
  - https://jamesfriend.com.au/pce-js/
- Mac
  - https://infinitemac.org/
Applied Technology
- Microbee
  - https://nanowasp.org/
Atari
BBC
- Micro
  - https://www.compumuseum.com/player.html?machine=bbcmicro
Commodore
IBM
- PC/XT
  - https://www.pcjs.org/machines/pcx86/ibm/5160/mda/
Sharp
- PC-1500
  - https://www.compumuseum.com/standalone/sharp-pc1500.html
- X1 Turbo
  - https://www.compumuseum.com/emularity.html?machine=sharp-x1turbo
Sinclair
- ZX81
  - https://www.compumuseum.com/player.html?machine=zx81
- ZX Spectrum
  - https://www.compumuseum.com/player.html?machine=zxspectrum
TI
- TI-99/4A
  - https://www.compumuseum.com/player.html?machine=ti99-4a
Xerox
- Alto
  - https://www.compumuseum.com/player.html?machine=salto
Tandy
- TRS-80 Model III
  - https://www.compumuseum.com/player.html?machine=trs80model3

There are also many emulators for applications and games. Here are a few that were of interest to me:

Commodore 64 Games Books from Melbourne House

2025-07-19T12:00:00+10:00

When I got my Commodore 64 for Christmas in about 1984 or 1985 it came with a book called Commodore 64 Games Book by Clifford and Mark Ramshaw, and published by Melbourne House.

This book featured 30 games which you had to type in yourself. Each was printed over at least a couple of pages. This is how things were done at the time.

Because it was expected that you were going to make some mistakes typing in hundreds of lines of code, the first program in the book was Chexsum -- a program that you could use to check if you had any errors when you finished typing in one of the games.

The idea was, you would type in Chexsum, save it and then load it first before typing in any of the games. Then you would run the Chexsum code -- located at a line number higher than any of the games needed -- and it would produce a list of numbers that you could compare with the Chexsum codes at the end of each game listing. If any numbers didn't match then you could see which line was wrong and fix it.

After the excitement of a new Commodore 64 and a few games wore off, I looked through this book and identified Flight Simulator as the first game I was going to try. Being about twelve or thirteen, and having little or no experience with typing meant that this was a very long process and I'm sure Chexsum probably solved many problems.

If you have played this Flight Simulator game yourself, then you can probably imagine my disappointment when I first played it and found that it wasn't much of a simulator -- you are just flying in the dark and the whole game just comes down to a few things being right at landing time.

I persisted and over months or years gradually worked my way through most of the games, maybe all of them.

Most of the games are pretty ordinary, but the book does teach you about BASIC games programming and what can be achieved on a Commodore 64.

I never knew until in recent years -- forty years later -- that there was a second book. I haven't looked at these games yet.

You can read the first book and the second book online at the Internet Archive.

Some of the games can be found in games databases and some can be downloaded.

Someone (YouTuber OldSkoolCoder) has also typed in the games so you can find the listings for the first book and the second book on a GitHub. However, I did try a few of these in the VICE emulator and found that they needed a little work with some of the special characters and text before they would work.

Radio Shack digital calculator/databank watches history

2025-01-09T12:00:00+10:00

Micronta 63-5054

Eight-digit 4-function calculator, mineral lens, dual time, calendar, 1/100 second stopwatch with lap time, 24-hour alarm

1983 - $39.95
1984 - $31.95
1985 - $19.95
1986 - $15.95
1987 - $12.95
1988 - $12.95

Micronta 63-5060

Phone directory/calculator watch. Stores 40 phone numbers. Recall by entering party's name. Full-function calculator, calendar, 12/24-hour display

1985 - $29.95
1986 - $24.95
1987 - $24.95
1988 - $24.95

Micronta 63-5062

LCD calculator/alarm. Features 24-hour alarm, 4-function 8-digit calculator, autocalendar, stainless-steel band, with RS CD2032 battery

1989 - $12.95

Micronta 63-5059

LCD calculator watch. LCD displays time./date. Has travel alarm. With RS 389 battery.

1990 - $12.95
1991 - $12.95
1992 - $12.95

Micronta 63-5071

LCD calculator watch. LCD shows time/date. 24-hour travel alarm. Features 4-function 8-digital calculator. With RS389 battery.

1993 - $12.95
1994 - $12.99

Radio Shack 63-5021

8-digit caclulator, alarm, hourly chime, calendar, timer. Includes battery
Available Oct 30, 1994

1995 - $14.99
1996 - $14.99
1997 - $14.99

From the 1996 catalogue, Casio calculators were added to the range. These are not covered on this page.

Radio Shack 63-5087

New alarm watch with data bank. Stores namesd and phone numbers. Also has calculator, stopwatch, four alarms, would time clock, dual time

1996 - $29.99

Radio Shack 63-5085

New flip-top watch with calculator. More features than meet the eye. A stylish and classic analog watch on top with an 8-digit calcutor, digitsal watch and stopwatch hidden udnerneath. Handy bulit-in alarm helps keep you on time. Hourly chime, month/day/date calendar

1996 - $27.99

Vintage clock/radios and my Soundesign 3834-A

2025-01-07T12:00:00+10:00

As a child in Australia in the 1980s, I was always interested in technology including video games, computers, watches and audio/visual equipment.

In the early 1980s, when I was about 12, I went with my family for a holiday to the USA, and one of the things I wanted to get when I was there was an interesting clock/radio.

One of the first places we stopped at was New York City and it wasn't long before I convinced the family to look in some electronics stores and came across this most amazing clock/radio: the Soundesign 3834-A.

This looked like it belonged on a spacecraft, with many buttons and a sleep horizontal design with angled display for the time and tuner.

Unlike most clock/radios, this one also had a cassette recorder with built-in microphone.

I convinced my father to buy it and brought it back to Australia where we discovered that we needed an expensive USA to Australia (110V to 240V) power converter.

But once up and running, I loved this clock/radio for many years, although I can't recall whatever happened to it.

Note that the photos are not mine and are from a USA eBay listing.

Vintage watches and my Radio Shack 63-5087 Multifunction Watch

2024-12-22T12:00:00+10:00

As a child in the 1980s I loved all sorts of technology including watches. I liked digital watches in particular, the more features the better.

I had many watches, although I can't remember many of them now, but I recall at least two calculator watches and some others.

I do remember the Casio solar-powered WL-10 that I had in the 1990s. I actually found this recently and although it still worked the screen was damaged and for some reason I sold it on eBay rather then keeping it, as I wish I had done now.

In addition to the usual digital watch functions, it also had five alarms.

(Not my photo)

But I do still have a Radio Shack 63-5087 data bank and calculator watch which was given to me as a gift by my then girlfriend, now wife, back in the 1990s.

It has a two line display with the day, date and month at the top, and the time including seconds on the larger second line.

Features include a calculator, data bank, four alarms, world time and stop watch.

Battery is a CR2016.

Mine has been stored for many years and when I found it recently I wanted to put it back in service.

Unfortunately, in addition to scratches, bumps and scrapes, the strap had disintegrated. I found a 16mm strap on Aliexpress but, being only a 20mm wide band, it looks strange and it also needed some cutting to make it fit. I also tried a couple of other straps but none fitted well and I am trying to find a better one.

The screws on the back of the case had corroded a little and one broke off. Many of the other screws are stripped, including the one that secures the battery.

Fortunately, it still works and the date defaults to 1988.

I couldn't find it in a Tandy Australia catalogue, but I did find the watch in a 1996 Radio Shack catalog from the US.

Update:

II tried a few watch straps and the one that suits the 63-5087 is one for the Casio W800H. There are a few versions of this strap but the one to look for is the one that is 18mm/24mm wide (some are 18mm/22mm).

The simplest and cheapest retrobright technique (but not the fastest)

2024-10-30T12:00:00+10:00

I've seen quite a few YouTube videos about retrobrighting and most recommend using hydrogen peroxide and UV light.

But I've also seen a few where they say you can just leave the item out in direct sunlight and the yellowing will eventually disappear or at least significantly improve.

This doesn't appear to make sense... Didn't the sun cause the damage in the first place? I'm not convinced, but apparently not because people have found that plastic items can go yellow even when stored away from light. And directly light is meant to have a bleaching effect that can lighten plastics.

The other day I came across an old telephone in my collection of electronics that had suffered badly and was a dark shade of yellow instead of it's original white, so I decided to give this a go myself.

I didn't take a before picture (oops) but my first photo is of the underside of the phone, which shows its' original white colour and the yellowing around around the more exposed surfaces. Didn't I say that it wasn't sunlight that caused the problem? Then why is the underside not yellowed?

Anyway, it was a reasonably hot spring day here in Sydney with lots of sunlight, and I was able to leave the phone in direct sunlight for somewhere around 8 hours. I covered a small yellowed section with some electrical tape so that I could see what if any difference the sun made.

At the end of the day it still looked very yellow and I didn't think there was any difference until I removed the electrical tape. This showed that there was actually a huge difference!

Further updates coming soon...

Some recent great stories from Retro Recipes

2024-10-12T12:00:00+10:00

I'm still watching YouTube videos about old computers like the Commodore 64.

Retro Recipes is a YouTube channel about retro computing and other nostalgia.

Recently the channel had some amazing stories that are well worth sharing.

The first one is about a programming language for the Commodore 64 that the host reviewed 40 years ago and never saw or heard anything about ever again. After being presumed lost to time, in a second episode a copy is found for sale.

The Commodore 64 Programming Language that Doesn't Exist | MicroText

The Amazing Programming Language Lost For 40 Yrs: C64 Microtext

The other story is about a television show about computing that ran in the UK in the 1980s that broadcast a computer program by flashing a light on the screen while the program was running.

Viewers were instructed on how they could build a receiver prior to the broadcast and type in a small program to receive the program that was to be transmitted.

Many people tried but were unsuccessful back in the 80s. In this video the host attempts to receive the program today using an old copy of the broadcast.

Decoding A Program Sent From The Past