This is so cool I just have to share it with you all. Today I picked up a parcel from the post office. I’ll let the pictures tell the story…
So now I am the proud owner of two brand new ZX81 kits and a couple of new ZX81 books. The kit boxes have been dinged slightly, but considering these are about 25 years old, that’s to be expected. This is so fricken cool! 8^)
A few days ago I started to see blog posts about three new Atari 2600 keyring games appearing all over the blogosphere. These games can be found over at ThinkGeek.com and sound really neat - mini joysticks (or paddles) that contain two or three classic Atari 2600 games.
Then I stumbled across this thread over at AtariAge.com… Bugger! These sounded like a nice idea - shame about the implementation. 
I’ve been searching the internet for information on the Soord M5, but while there are a large number of hits on Google, there is not a great deal of technical information, unless you can speak Czech…
I’m trying to find the pinout for the power supply so I can builld a replacement because the Sord M5 I won on eBay didn’t have a power supply. The PS connector is a 6-pin DIN and the voltages are +5V, +12V and -12V so if I can work out which voltage goes to which pin I should be able to build a replacement easily enough. I did find a schematic in my searches so I should be able to use that to determine the voltages required on the pins of the power connector…
Today I picked up a parcel which had been waiting at the post office since last friday (unfortunately I have been out of action with the flu ) and it contained the Sord M5 I recently won on eBay. The Sord M5 is definitely an interesting little beastie and quite a rare one at that. In the years that I have been collecting old computers I haven’t come across one for sale, so I snapped this one up when I saw it. (Although to be honest, I probably paid too much for it…)
The Sord M5 is a cute little machine with a chicklet keyboard and this one is in excellent condition - some of the included tapes and cartridges are still sealed in fact! Unfortunately one thing that was missing from the box is the power supply, so I can’t fire it up and test it. At the moment there doesn’t seem to be a great deal of information on the Sord M5 on the ‘net, so coming up with a work-around for the power supply might be a bit tricky…
The town where I spent my high school years (1981-1986) was small and somewhat remote. There were no stores selling computers or video games in town. The nearest electronics store, such as Tandy (aka RadioShack) or Dick Smith Electronics, was a couple of hours drive away. As such, my friends and I had limited access to these cool toys. In fact, I can count on the fingers of both hands the number of people I knew who had either a computer or video game - I had a Vic 20; my brother’s ids had an Atari 2600; my best friend had a Commodore 64; a family friend had a Vic 20, Commodore 64, Philips VideoPac and one other game system I cant recall; the town doctor had a Dick Smith VZ-200 and later a Macintosh; another family friend had an Atari 800XL; another had a Coleco Adam; and there were a further couple of systems I had a chance to play with. So in some respects, I was lucky enough to be able to experience a number of different systems, but compared to some people who grew up in the same era, my access was somewhat limited. For example, I never got to use the Sinclair Spectrum, the BBC, Oric, Tandy TRS80 or the CoCo, nor did I get to play with the Arcadia 2001, Fairchild Channel F, Bally Astrocade, Nintendo NES, Interton VC 4000, or the Intellivision.
In recent years, thanks to eBay I have been able to acquire some of these systems which were so influential on home computer and video game development. Many of the early game systems in particular can be found very cheaply - in fact I have a HUGE collection of Hanimex/Radofin/Acetronic systems and their variants (aka 1292 Advanced Programmable Video System) which sell for as little as $5. Some systems however attract premium prices, among them the Dick Smith Wizzard (aka Creativision) and the Intellivison. (Although a few Intellivisions have been popping up lately and prices appear to be coming down.)
While emulation remains an option for some, another alternative can be found in the emerging “all-in-one joystick” market. These devices are not much bigger than typical joysticks and plug directly into your television, allowing you to play a number of classic games that you might not otherwise have access to. The variety of these devices is astounding - several based on the Atari 2600, a couple of Commodore 64 collections, a variety of arcade conversions (such as Jakks TV’s Namco series) and a couple of Intellivision models.
A few weeks ago I won an auction for an Intellivision 25 Direct to TV system for $9. Never having played any Intellivision games before, I was interested to see what they were like. I can’t speak for how representative this sampling of games is, so I will leave a review for a later post, but my initial reactions are reservedly positive. Compared to the Atari 2600, the graphics are definitely more detailed yet the gameplay is somewhat lacking. There appears to be a few bugs in the model I have, with some games resetting for no apparent reason and some of the games seem to be unfinished - for example, Motocross only has a single level/course which just doesn’t give the game any real replay value.
Overall, the Intellivision 25 is a neat little pick-up. I may start looking for other all-in-one joystick games to add to my collection even though my first preference is and always will be for the real hardware.
Have you had any experience with an all-in-one joystick? If so, leave a comment and share your stories.
While I personally prefer to use the real thing, it is smetimes handy to be able to fire up an emulator. I recently posted a link to a web-based ZX81 emulator, now it is the 64’s turn for the web-base emulation treatment. FC64 is an open source, Flash-based Commodore 64 emulator. It still needs a bit of work but looks pretty neat - a Commodore 64 in your browser! 
I finally found the magazine containing the details of the Micro-comp so I can now give you some more details. The magazine was a one-shot, called Six BD 679 Projects, and the first half contained details of six electronics construction projects based around the BD 679 Darlington power transistor, with the Micro-Comp taking up the remainder of the magazine. (I am at a loss to explain why the Micro-Comp wasn’t featured more prominently on the cover or in the title, but Talking Electronics is a weird mob…) The magazine was published in 1994 and reprinted articles and projects from the Talking Electronics magazine.
Talking Electronics is a local electronics hobbyist company based in Melbourne. Back in the early 1980s (IIRC) TE launched an electronics magazine, which saw some moderate success despite its irregular publishing schedule. In all, fifteen issues of Talking Electronics were published and TE also published a number of one-shot magazines, including six Electronics Notebooks (similar to Forrest M Mims’ notebook series), a two-part Learning Electronics, Digital Electronics Revealed, numerous model railway and FM bug books and a few compilations of popular projects form the Talking electronics magazines. The magazines were generally pretty good and I learned a lot of my electronics chops by studying and building the projects presented therein. On to the Micro-Comp…
When I picked up the BD 679 magazine it caught my eye not because of the cover (a nasty two-tone brown affair) but rather the “free” BD679 taped to the front. I was always the sucker for freebies. Flicking through the magazine, the one project that really stood out for me was the Micro-Comp. Ever since I had read about CPU design, I had wanted to try my hand at designing my own computer - the Micro-Comp seemed like a good place to start learning what would be required.
The Micro-Comp uses just three chips - a Z80 CPU, a 2732 EPROM and a 74LS273 as an output buffer. You can’t get much simpler than that! Input is provided by an 8-way DIP switch and two momentary on push buttons. In my earlier post I thought the DIP switches were to select the start address, but that was wrong. The DIP switches are tied to the data bus - the code in the EPROM must read the value of the data bus and use that to jump to the correct start routine on power up.
The clock speed is adjustable, using a trim-pot to adjust an RC network, and the speed can vary from 7.5kHz to 35kHz. As this is really only a “trainer” and not a serious, full-blown computer, adjusting the clock speed can be extremely useful in tracing signals and trying to understand what is happening throughout the system. It is possible to listen to the various bus lines using the audio probe (the fly-lead in the photo I posted in the previous entry) and tweaking the clock speed affects the frequency of the sound.
The programs included in the EPROM are:
Most of those probably sound quite dull and uninteresting, but if you’ve built the computer and study the code for each of these simple programs, you can learn quite a bit about the workings of a real computer. Studying memory locations, data busses, loops and timers, multiplexing displays and so forth are the real aims of this project and I have to say I did learn a heck of a lot by building this and playing with it. Unfortunately I never had an EPROM burner, so I couldn’t write my own programs to test - maybe that is something I should address when I get some spare time…
A number of extra programs and add-ons were made available through the magazine. Two that I know of that were published in the magazine were a Blackjack program and an add-on board to play noughts and crosses. IIRC, a RAM pack, non-volatile RAM, morse-code trainer and relay driver boards were also available.
I thought I knew a fair bit about Commodore computers, but so much of what I knew turns out to be wrong. At least, it’s wrong according to this guy.
I didn’t realise how little I knew…
I really need to organise my colllection of old skool computers and video games. In fact, part of the reason for this site was my desire to create on online system for organising such a collection - that’s why I registered the domain name OldSkoolComputing.com.
So what do I need this syetm to do?
Each item could have an information page (or pages) containing technical details, history, pictures, and any other relevant information that fits. Items should be able to be marked as “for sale” and the ability to create “want lists” would be handy. Plus I’d like to make this a multi-user system, so anyone can track their collections with the ability to search for other users and trade with them.
So does anyone have any thoughts on this idea?
If you never had a chance to play around with some of the real old skool hardware back in the day, and can’t afford to buy some old hardware off eBay (Sinclair ZX80s can fetch over $300USD for example) then emulation is probably your best shot. Personally, I love the feel of a real machine under my fingers - nothing beats responsiveness of a Sinclair keyboard! (Well… actually… everything beats the feel of a Sinclair membrane keyboard… But there is something to be said for hammering away on the real deal.)
A few days back I found a Sinclair ZX81 emulator online. This emulator is neat - it is written in Java and lives completely within a web page. You can even load and save your programs. There’s a reasonably good programming reference, just in case your Sinclair skillz are rusty and a nice collection of programs ready to try out. About the only things you’ll miss out on are trying to get the levels right on your cassette player so you can load the software, and the fun that comes with trying to tune your TV to the Sinclair signal… ;^)