Search found 13 matches

by roganjosh
Fri Jan 08, 2021 11:11 am
Forum: Sinclair Misc
Topic: Sinclair Scientific calculator
Replies: 2
Views: 484

Sinclair Scientific calculator

Having recently received a gift of a TI DataMath/Sinclair Scientific hardware emulator kit I built it yesterday (it's largely a SMD build). https://simpleavr.github.io/tms0800/index.html It works nicely (you hold key 7 whilst powering-up for Sinclair Scientific mode). What prompted me to post is tha...
by roganjosh
Tue Dec 29, 2020 6:23 pm
Forum: Hardware
Topic: Faulty dk'tronics KEYBOARD
Replies: 8
Views: 352

Re: Faulty dk'tronics KEYBOARD

I can't improve on Moggy's excellent reply, just relate my experience The switches are easy to clean. I ended up dismantling and cleaning all 50 or so switches on a Dk'tronics keyboard I bought off ebay a couple of years ago. Approximately three had failed and most of them were showing a higher resi...
by roganjosh
Mon Sep 07, 2020 5:13 pm
Forum: Sinclair Misc
Topic: Jupiter ACE (again)
Replies: 123
Views: 73150

Re: Jupiter ACE (again)

I am wondering what ribbon cable length will be tolerated, I guess I can just try and see ;) There are a few variables affecting the length tolerance of course and you may well have to suck it and see. However, as an example of length , here is an ACE backplane/expansion-extender designed and built...
by roganjosh
Sat Jul 04, 2020 11:34 am
Forum: Software
Topic: DISACS daughter of DIS-ACSEM
Replies: 0
Views: 6014

DISACS daughter of DIS-ACSEM

It felt wrong, having written a replacement for ACSembler, not to write one for the missing-in-action ACS Software disassembler DIS-ACSEM. So, here is DISACS. disacs.zip In some ways, although most disassemblers look pretty much the same, the link here is a little more tenuous given that, in this ca...
by roganjosh
Mon Jun 22, 2020 3:27 pm
Forum: Software
Topic: Acsem son of Acsembler
Replies: 0
Views: 5804

Acsem son of Acsembler

Here is a recent rewrite of the MIA assembler, Acsembler, I wrote in the infancy of the ZX81 - and which was marketed by ACS Software, hence the odd-looking name. acsem.zip I mentioned the ACS Software stuff a couple of years ago when I joined this forum, and was hoping some of the titles might have...
by roganjosh
Thu Feb 07, 2019 9:32 am
Forum: Hardware
Topic: Jupiter Ace - Case Dimensions
Replies: 19
Views: 5835

Re: Jupiter Ace - Case Dimensions

I built the SDHC interface using a PIC18F25K40 which is on my main PCB along with all the other standard ACE chips. The interface relies on there being a ROM between e000-ffff to contain the low level code for communication between the Z80 CPU and the PIC, plus the new FORTH words which use that cod...
by roganjosh
Sat Feb 02, 2019 9:31 am
Forum: Hardware
Topic: Jupiter Ace - Case Dimensions
Replies: 19
Views: 5835

Re: Jupiter Ace - Case Dimensions

That looks like a lovely neat idea. I did a similar thing last year for my ARV1 (Ace Revamped) design but in a much bigger case - a dk'tronics keyboard one. That has the Jupiter Ace circuit with the following changes. a) ROMs are AT28C64-15 - one at 0-1FFF is essentially the ACE ROMs in one chip, th...
by roganjosh
Mon Jul 23, 2018 7:54 am
Forum: SALES
Topic: ZX81 ULA
Replies: 76
Views: 41495

Re: ZX81 ULA

I don't get it :?: It does appear rather out of context with the original exchange having been a while ago, and likely exacerbated by my no-smiley policy. Explaining humour is generally a very bad idea though. As for smileys, opinions differ and one should certainly not be militant about such thing...
by roganjosh
Sun Jul 22, 2018 6:18 pm
Forum: SALES
Topic: ZX81 ULA
Replies: 76
Views: 41495

Re: ZX81 ULA

Lardo Boffin wrote: Wed Jul 04, 2018 10:59 am I’m not paranoid. They are out to get me. :? :D


Ah, yes, quite right, my mistake. I forgot your distinction. I believe you. Honestly.


Alan
by roganjosh
Sun Jul 22, 2018 10:12 am
Forum: SALES
Topic: ZX81 ULA
Replies: 76
Views: 41495

Re: ZX81 ULA

Lardo Boffin wrote: Sat Jul 21, 2018 12:36 pm Got one! :D

Congratulations! Keep up that paranoia.


Alan