Hi Mike,
Something's wrong on the A3 memory address line, on the ULA or the ROM ship.
If you type "R", is there 3 displayed characters ? (to check if the BASIC/RAM is ok)
Type "V" then newline, to display "0/0"...
Check R18-R26 resistors. (A3'=R25)
Search found 1941 matches
- Thu Nov 23, 2023 10:15 pm
- Forum: Hardware
- Topic: ZX-81 Corrupted text display
- Replies: 26
- Views: 20565
- Sun Nov 12, 2023 11:17 am
- Forum: Welcome Area
- Topic: Hello from France II
- Replies: 4
- Views: 4851
Re: Hello from France II
Welcome aboard Jean-Robert.
How is your fiend Yannick?
How is your fiend Yannick?
- Sat Oct 28, 2023 2:12 am
- Forum: GAMES
- Topic: Halloween Game "Spin the Skulls"
- Replies: 1
- Views: 4463
Re: Halloween Game "Spin the Skulls"
Thanks Greg,
Remember me a jackpot game.
Good job.
Happy Halloween day...
Remember me a jackpot game.
Good job.
Happy Halloween day...
- Sat Oct 21, 2023 5:16 pm
- Forum: Development
- Topic: A scanner for you Zx81/Specturm.[WIP/DIY]
- Replies: 24
- Views: 14040
Re: A scanner for you Zx81/Specturm.[WIP/DIY]
Motor speed: Cylinder max speed turn around 1 rotation per second. The speed variator can reduce this speed at -1/4= 0.75 rotation per second. 1RPS(Second) =60RPM(Minute) Cylinder to the motor: 40touth/8tooth= 5 multiplier. Motor to the cylinder: 8tooth/40touth= 0.2 multiplier. 60RPM x 5= 300 RPM 3...
- Fri Oct 20, 2023 11:02 am
- Forum: Development
- Topic: A scanner for you Zx81/Specturm.[WIP/DIY]
- Replies: 24
- Views: 14040
Re: A scanner for you Zx81/Specturm.[WIP/DIY]
The sound of a picture challenge : Simply link the resistor output on a cheap PC USB sound card (2$) to avoid burning the main inboard sound card... The positive or negative low frequency signals can destroy the sound card ! The voltage had to be less than 5v to avoid to saturate the sound card rec...
- Fri Oct 20, 2023 10:36 am
- Forum: Development
- Topic: A scanner for you Zx81/Specturm.[WIP/DIY]
- Replies: 24
- Views: 14040
Re: A scanner for you Zx81/Specturm.[WIP/DIY]
ATARI ST Card (article's PCB):
Kicad v.6 & Gerber files: Note:
In the article, the component's side in the top view is false.
The photo gave the right component side.
Kicad v.6 & Gerber files: Note:
In the article, the component's side in the top view is false.
The photo gave the right component side.
- Tue Oct 17, 2023 4:05 pm
- Forum: Development
- Topic: A scanner for you Zx81/Specturm.[WIP/DIY]
- Replies: 24
- Views: 14040
Re: A scanner for you Zx81/Specturm.[WIP/DIY]
GERBER/Kicad 6 project (- Mon Oct 16, 2023 12:42 pm
- Forum: Development
- Topic: A scanner for you Zx81/Specturm.[WIP/DIY]
- Replies: 24
- Views: 14040
Re: A scanner for you Zx81/Specturm.[WIP/DIY]
For the AMSTRAD CPC 464/6128: (using a photodiode BWP 21 Telefunkel or a photoresistor = 2 colors)
http://abandon.pcbs.free.fr/mageco.htm
- Fri Oct 13, 2023 8:42 pm
- Forum: GAMES
- Topic: I have typed in the entirety of 3D bowling for the zx81 for archive purposes
- Replies: 2
- Views: 4681
- Thu Oct 12, 2023 10:50 am
- Forum: Development
- Topic: A scanner for you Zx81/Specturm.[WIP/DIY]
- Replies: 24
- Views: 14040
Re: A scanner for you Zx81/Specturm.[WIP/DIY]
Wings3D file only (All Project):