Sinclair ZX80 / ZX81 / Z88 Forums

Hi Mark Thanks for your reply - I am aware the differnce between mono/stereo Jack plugs/sockets. PC soundcard: stereo 3,5mm jack socket. Your Computer: 2 phono plugs (note MIC/EAR phono sockets without gnd connection, as the case is for the monitor socket) I used the microphone input on the soundcar...

Next step: save/load programs. Dont have a mono casette recorder (anymore), so the obvious: use a laptop soundcard as casette recorder. Unfortunately without any luck. Until now i have not had a scope on the MIC signal, but the PC recording SW shows only noise, and when SAVE- ENTER, a little change ...

GCHarder wrote: ↑Sat Jun 25, 2022 7:39 pm Circuit board picture and schematic for the PC8300...

https://archive.org/details/SyncWareNew ... 9/mode/2up

PCB layout and a more detailed schematic, compared to a german version found a few weeks ago, super!
Thanks GCHarder….

Do you mean that the PCB mounted socket has no 0V/GND connection? Or do you mean something different? Mark “Do you mean that the PCB mounted socket has no 0V/GND connection?” Excactly, same thing with socket “EAR”. I will take a picture one of the upcoming days, of both Lambda 8300 and Your Computer.

Lambda system variables and other specs here:
https://problemkaputt.de/zxdocs.htm#lambda8300

In this thread, a zx81 made “RAMTOP program” showing the amount of available RAM.
Works fine on my Lambda 8300 / Your Computer.
viewtopic.php?f=7&t=3876&p=47230&hilit=ramtop+8300#top

Hi there Yesterday i tried to save a small basic program, from my 8300 via MIC connecter/phono-jack cable to a PC soundcard. When SAVE, only noise came into the PC’s recording program. I discovered that no schield (GND) was connected from mainboard to the phono socket - only signal wire (center pin)...

Not sure what you mean. There is no command to check RAM. You may use PRINT PEEK 16389 which gives 68 for 1k and 128 for 16k RAM. This is the dirty variant. ;) PRINT PEEK 16389*256+PEEK 16388 PRINT PEEK 16389*256+PEEK 16388-16384 This should give RAMTOP address (first line) and RAM installed/availa...

Hi 1024MAK This forum is floating with knowledge. Already used several hours scanning the treads, and when posting something new - a nice well-founded answer appears almost instantly. I am a little bit amazed how many chip-versions and board configurations, this "toy-store" computer is produced/sold...

My "Your Computer" chipset:

CPU: NEC Japan D780C-1 8344XD
ULA: C4005 8440
ROM: AMI 8436HJ 10830-21103-01

Apparently, the 4 block RAM (2114) is "missing" on the computer.
Note: No (Your Computer) label on the front, nor any seriel placard on the back center.