Old TV as a ZX80 monitor may not be optimum
Re: Old TV as a ZX80 monitor may not be optimum
Yup that does indeed seem to be the wee beasty!
- 1024MAK
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- Location: Looking forward to summer in Somerset, UK...
Re: Old TV as a ZX80 monitor may not be optimum
Yeah, that’s fine. zebranyc (Zebra Systems) has been selling Timex/Sinclair bits for some time.Creator wrote: ↑Thu Jul 28, 2022 4:00 pm Looks like the same product. https://www.ebay.com/itm/174949505611
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
- 1024MAK
- Posts: 5146
- Joined: Mon Sep 26, 2011 10:56 am
- Location: Looking forward to summer in Somerset, UK...
Re: Old TV as a ZX80 monitor may not be optimum
The topic where I looked at one version of the video boards based on a NE555 is here. But note that there may well be a number of different versions from different sellers.
Mark
ZX81 Variations
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
ZX81 Chip Pin-outs
ZX81 Video Transistor Buffer Amp
Standby alert
There are four lights!
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb
Looking forward to summer later in the year.
-
- Posts: 2182
- Joined: Sat Nov 26, 2016 2:42 am
Re: Old TV as a ZX80 monitor may not be optimum
Just another voice in support of Pokemon. Or picture…
These arrived today. I think this makes either 55 or 60 of these I will have fitted. The keyboards are excellent as well!
These arrived today. I think this makes either 55 or 60 of these I will have fitted. The keyboards are excellent as well!
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
-
- Posts: 2182
- Joined: Sat Nov 26, 2016 2:42 am
Re: Old TV as a ZX80 monitor may not be optimum
Sounds pretty good to me! I have used TZXDuinos which don’t load any faster than tape in the past. They also don’t allow you to save files. So this would be a big improvement.Creator wrote: ↑Thu Jul 28, 2022 3:27 pm
Laedo Boffin
My SDcard project (Xiao, Op Amp, software) is kinda interesting but has its limits, really just a 'can I make this work' kinda thing. It uses existing Load & Save commands so really no speed increase. On Save it monitors the data stream storing all valid pulses then when complete parses and converts to 1's & 0's which are saved to SDcard file so savable ZX80 program size is limited by available memory (currently 32k Xiao). An improvement would be to monitor / parse on the fly but that presents some issues I haven't tackled yet but may in the future. Load is just reading the SDcard file and generating proper pulse patterns for the stored 1's & 0's.
ZX80
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
ZX81 iss 1 (bugged ROM, kludge fix, normal, rebuilt)
TS 1000 iss 3, ZXPand AY and +, ZX8-CCB, ZX-KDLX & ChromaSCART
Tatung 81 + Wespi
TS 1500 & 2000
Spectrum 16k (iss 1 s/n 862)
Spectrum 48ks plus a DIVMMC future and SPECTRA
Re: Old TV as a ZX80 monitor may not be optimum
By curious happenstance I've just ordered one of those clicky keyboards, hope they are worth their salt unlike the dreadful ZX80 membrane replacement I wish I hadn't bothered with, granite keys would be kinder to the old digits than that horror .
Re: Old TV as a ZX80 monitor may not be optimum
OK, ordered the video card, gotta be an improvement. Eyeballing the keyboards ! Went looking for some books on machine language for the ZX80 & ROM deciphering. Haven't done much of either of those since my TRS-80 days, could be fun.
Re: Old TV as a ZX80 monitor may not be optimum
This is the book for machine code on both ZX80 and ZX81.
http://www.users.waitrose.com/~thunor/m ... index.html
Re: Old TV as a ZX80 monitor may not be optimum
The ZX80 ROM disassembly can be found here...
https://k1.spdns.de/Vintage/Sinclair/80 ... source.txt
https://k1.spdns.de/Vintage/Sinclair/80 ... source.txt
Re: Old TV as a ZX80 monitor may not be optimum
Received and installed the ZX8-CCB module but sadly there are issues. Seems my video signal is too low to properly drive the circuitry. Level is about 1.1v with or without the OEM circuit connected & about 1.4 v with nothing connected. ZX8-CCB paperwork says a 1.4v signal is needed. I don't have a schematic that shows what I need to look into this (circuit upstream from the ZX80 onboard video 'can'). A pointer to such if it exists would be appreciated. Other comments also welcomed.
EDIT : schematic found http://k1.spdns.de/Vintage/Sinclair/80/ ... matics.gif
EDIT : schematic found http://k1.spdns.de/Vintage/Sinclair/80/ ... matics.gif