First post, by brassicGamer
- Rank
- Oldbie
Think of the biggest names in PC clones in the '80s: Compaq obviously, HP, Dell, Zenith. What, what? Yes, after buying out Heath, Zenith had the 2nd largest share of the PC clone market after Compaq thanks to a shrewd decision to sell to big organisations like the government and their agencies (military, navy, etc) and manufacturing their own monitors. By undercutting the XT, offering faster processing speeds, but still providing solid build quality and good support, they were able to effectively sneak in the back door of the PC market.
Their most popular model was the Z-150, which was released in 1984 and kept up with developments over the next few years. They even released an AT Clone. British Telecom (BT) signed a deal in the mid '80s to use rebadged Zenith Z-159s in their call management solutions and one of these is my most recent acquisition. I'm super excited about it, as it's my first 8-bit machine, and was relatively cheap compared to what I've seen genuine IBMs go for. I was also fortunate enough to have found a dumped Commodore 1084S monitor a couple of years ago, but I'm lacking a genuine IBM CGA card and XT keyboard. I have both a CGA and EGA clone though so that'll do for now.
Architecturally it's an interesting clone:
- It uses an ISA backplane. This gives it a smaller footprint than the XT.
- It includes two proprietary cards which, although they use the AT bus, are wider than standard cards.
- One is the CPU card and includes a Fujitsu 8088-2, which can be physically switched between 5MHz or 8MHz.
- The other is the floppy and serial controller.
- The RAM is on a separate card but is required for the computer to run. As it includes both the conventional memory and EMS (and parallel), I don't know whether an alternative card would work.
- It came with a Novell ARCnet card which I have removed.
- I've swapped the Paradise EGA card out for a 'dual graphics' MDA/CGA card and am using composite at the moment.
- Although a fixed disk was an option for this model, this one comes with 2x 5.25" drives so at least I won't need to swap disks between games and the OS.
I spent the last two evenings cleaning the computer inside and out, particularly the PSU as that was the most likely component to fail and the filthiest. I think its main user was a smoker! The scrapper I bought it from said it powered on but that's all they could say about it. The fan works perfectly and is very quiet. After checking everything else over with a fine tooth comb, I powered it up and got an error about the floppy controlled being bad. This did not bode well and replacing it with an IBM alternative didn't work. After feeding the error into Google and finding an article in PC Mag from 1984, I tried reseating all the chips and... it worked!! All I need now is an XT-compatible keyboard and some more 5.25" disks so I can experience some genuine CGA gaming goodness!!! Seriously, it's taken less time to get this thing working than a 486 and it's been more fun.
The seller's main pic:
The CPU card (sadly no co-pro, not that it's needed but, you know...):
The system cleaned up and powered on:
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