Tatung Computer Forum

I was sidetracked a bit but now keyboard problems are delaying me. Some number keys get stuck / spring back very slowly, the P key doesn't work at all (not helpful when trying to run SP1.COM) and all the other keys that do work play a tune when I press them. Any ideas?

Aside: is there a list of which ICs are socketed for the Einstein and 256?

Tony Brewer wrote: ↑Mon Feb 06, 2023 8:06 pm I was sidetracked a bit but now keyboard problems are delaying me. Some number keys get stuck / spring back very slowly, the P key doesn't work at all (not helpful when trying to run SP1.COM) and all the other keys that do work play a tune when I press them. Any ideas?

Aside: is there a list of which ICs are socketed for the Einstein and 256?

Sticky keyboard seems to be the bane of every Einstein. Contact cleaner helps a bit and anecdotally it’s affected by the cold so maybe it’s helped by gentle warming? Proper fix seems to be a complete strip down of the keyboard though.

Some of my Einsteins are affected by the tuneful keyboard as well, I haven’t investigated the issue though but it doesn’t affect the operation of the machine.

I've seen the list of the ICs in the TC01 Hardware Manual, but nothing about socketed ICs or the circuit board of the 256 anywhere.

Having checked some TC01 circuit board photos, it would seem the only socketed ICs are the MOS, spare ROM socket and the 1770 floppy disc controller.

Photos here https://www.nightfallcrew.com/27/12/201 ... ?nggpage=3

Well on my 256, Tony, the CPU, the VDP, all ram (both video and main ram) and the MOS rom are socketed. Everything else, the CTC, the PSG, disk controller, etc. are soldered to the board.

Not sure if that is representative of all 256s, as I only got mine in 2021 and it had been opened (disk drive fiddled with).

Apologies for not posting here for months. Unfortunately my Meniere's symptoms returned in the spring and I have decided to sell all my Einstein hardware and software, which will allow other people to enjoy the Speculator and Silicon Disc.

Something that is completely free is the source code for the Speculator that I'm now putting in the public domain: I used Microsoft M80 and L80 to assemble and link the source files, the same as was done at Memotech. There are two .sub files to make assembling & linking easier. Source code assembles to match object code perfectly, e.g. with MyZ80.

Sorry to hear about your Menieres syndrome, Tony. Thanks for putting this out here and thank you for all the hard work in reversing engineering the Memotech version after the source was lost.

I hope your symptoms become more manageable sometime soon.

Sorry you’ve been unwell Tony.

I’m sure the Speculator and Silicon disc will live on with people enjoying them.

Very sorry to hear about your Meniere's syndrome, Tony.

Thanks for putting the source code in the public domain.

I look forward to exploring how the Speculator is implemented in more detail.

Sadly my health is still not good. Time to sell all my Einstein stuff including Speculators (ESP) and Silicon Discs (ESD). Please see full list below. Assume that I can't support any of this in the future. For ESP & ESD, copy PALs and program GALs from the one PCB of each that works. Also for ESD copy ROM that is in second ROM socket inside Einstein.

I would like to sell everything Einstein as a job lot to one buyer. I don't have a car and I can't take items to post office. Items could be collected from here in Gloucester. Could probably package items to be collected by courier but I can't be responsible for any damage in transit.

Items for sale:

1.
Tatung Einstein TC01 computer
original packaging
some keys stick, a few don't work

2.
Tatung Einstein TM01 colour monitor
fully working when testing Speculator
original packaging (not very robust)

3.
Cardboard box containing following:

Tatung Einstein TK02 80-column card
original box with two plastic spacers
fully working

Einstein Speculator boards (no cases)
Fully assembled, working = 1 (PCB and ribbon cable has tick mark)
Fully or partially assembled, not working = 6
Bare PCBs = 6
Total boards = 13

Einstein Silicon Disc boards (no cases)
Fully assembled, working = 1
Fully socketed, no chips, not working = 12
Bare PCBs = 92
Total boards = 105

Einstein Silicon Disc instructions and stickers for case (no cases)

Multiple ribbon cables with 60-way IDC sockets
Most do not work but could perhaps by cut and sockets reattached

Original Einstein 3" diskettes

My own work 3" diskettes

Original Einstein manuals

Video cables to connect TC01 & TK02 to TM01

Einstein PAL reader
Prototype board
Connects to User I/O port

Einstein micro SD card interface
Prototype board
Connects to User I/O port

Z80 CPUs with a PAL stuck on top
For use with Einstein 256
PAL enables double-sided diskettes to work
Not sure I ever completed firmware

4.
Zenith 12" amber monitor
NTSC monochrome composite input, 15MHz
Works with 80-column card
Original box

5.
Cardboard box containing the following:
185 x 60-way right-angle PCB headers
Light blue (as shown in earlier pics)
Way more than required for bare PCBs
but I have no further use for them

Optional extra:

6.
Memotech DMX80 printer
original box
manual second-hand quality
printer in brand new condition

N.B. Using a computer makes me very dizzy quite easily.

Hi Tony

Sorry to hear about your health and having to sell all your Einstein stuff.

Sadly I don’t have the money, space or time but what are you looking to get for it all?