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8032 Multifont

Feature creep:
If you replace both rows with 4164 chips you can keep CAS as is, and just add a single MUX to the additional address line to be able to switch between 4 32k banks. Add a bit more logic, copied from the 64k add-on board that converts an 8032 to an 8096, and you have created an 8096 of sorts. Add a bit more logic inspired by the 8296 and you could use the last 32k to emulate extra ROMs loaded from disk. The only 8296 feature you won't get is more video RAM. (Can't remember the details but IIRC it can use 4k for video, I.E. $8000-$8FFF, I.E. two pages of 80x25 text).

This could all be done in incremental steps. First just replace the DRAMs and tie the additional address line to ground or VCC. Then add the various parts to make it similar to an 8296.
http://www.6502.org/users/andre/petindex/8x96.html
 
thanks, yes I was just thinking there might be a simple way to just use eight 4164 rather than 16, but having a look over the schematic and I'd need to start adding components to AND the CAS and then find some way to hit the bank select directly for A7, and at that point I'd probably be better off doing that 96k mod :)
I'll just pull all 16 of the 4116 and socket in 16x 4164 and do as you and Dave described (the same mod I did on my CBM 4032) ....... I was just trying to be lazy and only fit 8 sockets :)
 
You could probably just disconnect A14 from the DRAM address decoding, holding it low or high depending on which bank you populate, and connect the actual A14 signal to the additional RAM address line. That way would would use the upper and lower 16k parts of the 64k RAM space, if you really want to have one single 4164 bank.

I don't know if this was a mod that anyone did back in the days, and thus can be considered somewhat period correct? Compare with afaik some people modified their PC motherboards to take more RAM, rather than buying expansion cards (say with 384k to go from 256k to 640k).
 
well, we're back. I've pulled the 4116 and exactly as Dave said, UA9 was faulty. Rather than mess about I've just chucked in a full row of 16x 4164 ... however I thought I had a stash but it turns out I only had a load of "China specials" where they sand off what the real chip was and just label them up as some generic make, and there were at least 4 different unknown brands in the pile I had. Of the first 16 I grabbed 5 were dead, so I didn't get my hopes up much, but I've chucked them in and we're back in business. the pettest ROM runs though fine and the memory passes all the runs I left it doing. No idea if I've lucked out and all these random chips support 128 row refresh of if there's some looming memory corruption that'll happen at some time. Either way, I'll get some "real" chips on order.
While the test ROM was up and running and the characters were mapped out on screen I had a go with the font selection, and there's really not much to the changes. Here's the four font banks
4fonts.jpg
I've still got a couple more tests to run and then I'll get it all back together in it's repainted case and start looking at this RS232 board.
 
Excellent news.

So my UA9 'educated guess' was correct then...

I wish I was that lucky with this little ESP8266 project I am doing today... The user interface was straightforward. I am now involved in communications, hashing and encryption/decryption algorithms...

I think my brain is now fried for today - so some dinner and a glass of wine are called for. Never drive, operate heavy machinery or program after the intake of alcohol!

Dave
 
That is a weird font with uppercase German ÜÖÄ located where you'd expect äöü, i.e. they are not only in the wrong case but also in the wrong order (as compared to ISO 646
It seems like some ad-hoc attempt of sorts. Or maybe someone had access to a weird non-standard printer?

A tangent: The German and Swedish Wikipedia pages about ISO 646 contradicts each other re $ or ¤.
Another tangent: Recently I've found that the history of national variations of character codes and keyboards layouts seems poorly documented online. When searching these topics, I've kind of found that at best it's possible to find the name of some national standard that defines things, and also just search for pictures of old keyboards/typewriters. I.E. translate "old typewriter" to various languages and then input that to google image search.
 
yes spot on with with the DRAM assessment... also looks like I wasn't that lucky with the row refresh, or I've hit the next issue :) after leaving it running for a couple of hours while I made up a null modem cable that would fake carrier detect it's now started "snowing" quite a nice effect as it changes direction, it's currently snowing upwards :)
snowing.jpg

On the font front, it came with one of those HUGE A3 daisywheel printers (27kg ... I weighed it) I've not checked what font set that has, could relate to one of the ones I have here.
 
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