Search found 20 matches

by gregctaylor
Sun Aug 12, 2018 7:07 pm
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Re: Still faulty 80K

About £15 plus insurance dependant on value but that is free up to £50.
by gregctaylor
Sun Aug 12, 2018 4:01 pm
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Re: Still faulty 80K

Another gripping instalment! For those not in the know (me included until a little while ago), most home computers of the time used the system clock for everything, dropping clock frequencies by additional chips or by using the processor itself to time things. The Sharps are quite different. They us...
by gregctaylor
Sat Aug 04, 2018 3:43 pm
Forum: Hardware
Topic: SANYO TRC-1148 Recording volume
Replies: 1
Views: 416

Re: SANYO TRC-1148 Recording volume

I assume you are connecting the computer earphone out to the tape recorder microphone in? The output is WAY too high. On my laptop, I have the earphone output set to between 3 and 5 (Windows 10) so extremely low. If you are intending to save to tape so you can then play on a physical computer (eg MZ...
by gregctaylor
Thu Jul 26, 2018 11:27 am
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Re: Still faulty 80K

Moving forward slowly. Replacing the 7404 and the tuning capacitor means I now have a good clock on the Z80. Still no change to the display though. I will swap out the Z80 a second time (in case the lack of clock was hiding the fact the Z80 had also failed) but, if not, will then attach the video ci...
by gregctaylor
Sun Jul 08, 2018 5:02 pm
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Re: Still faulty 80K

Latest gripping update!! I began by checking pin 6 of the Z80, NOT_CLK, at which the scope should have shown a 2MHz clock. I did get something at around 50Hz (bit of mains hum I think) with very low voltage and a very irregular shape. Pulled the Z80 to see if that was at fault. Same poor clock and, ...
by gregctaylor
Sat Jul 07, 2018 3:28 pm
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Re: Still faulty 80K

Good idea to check the Z80. I have spares as well which are for a different project but easily purloined.
by gregctaylor
Sat Jul 07, 2018 1:09 pm
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Re: Still faulty 80K

Thanks for the ideas. No M-ROM was not tested but my original shows exactly the same pattern so don't think it is that. Tried SG but no sound, nor out of my fully working 80A either. Perhaps I am doing it wrong? Is it SG then [Return] or just SG? I shall try the schematic and also check out the actu...
by gregctaylor
Fri Jul 06, 2018 2:33 pm
Forum: Hardware
Topic: Still faulty 80K
Replies: 11
Views: 716

Still faulty 80K

After much work and testing, it is not main RAM, I have swapped for new VRAM, swapped M-ROM and CG-ROM. Same error all the time. Have had a good look at the screen and the output is: code 10100011b (I think) then a space then either code 1100011b or 11100011b then a space then code 10100011b and so ...
by gregctaylor
Sat Jun 23, 2018 4:08 pm
Forum: Hardware
Topic: Fixed Sharp but not yet!
Replies: 5
Views: 571

Re: Fixed Sharp but not yet!

Just got back off holiday to some new VRAM chips. Have socketed the board and replaced and ...... (builds up tension ......)
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no change . *?!!!****???!!!

The next option must be the boot ROM (EPROM?) but I don't have an EPROM blower so a bit stuck. Anyone any ideas or can help me out?

Greg
by gregctaylor
Sun Jun 17, 2018 5:34 pm
Forum: Emulation
Topic: idea: custom keyboard for MZ emulation
Replies: 7
Views: 1336

Re: idea: custom keyboard for MZ emulation

An easy solution is to buy a really cheap USB keyboard, a compact one can look even better. Then print keytops, you can sometimes find images which you can scale up and print. I have found the easiest way to do this is to brush paint a little lacquer on each key, stick the paper keytop to the sticky...