Sinclair ZX80 / ZX81 / Z88 Forums

I just saw a cheap Lambda 8300 for sale on eBay, so I thought to share. This sale is not connected to me. Just sharing.

https://www.ebay.de/itm/315071989986

My "model" program contains a routine called FLASHOUT, which copies in its entirety the normal 16-32K program area to the higher one. Why? : A NEW command does not clear the upper memory area. So if, while working on a still dangerous program, I FLASHOUT the code and the computer subsequently crash...

We talked about it back in 2018.

https://www.sinclairzxworld.com/viewtop ... =10&t=3013

Great to see a new game for the Lambda 8300!

You can also use the online emulator JSzeddy, that supports both old and new ROM of Lambda 8300.

Know that this game is only working on the new rom for Lambda 8300.

From what I've seen online the sync signal should not be 0v. It’s because the ZX81 does not follow the composite standard. It sends a signal where the difference from bottom of signal to top of signal is ok. Old TVs think this is ok. It does this to avoid making a more complex circuit that sends ne...

This issue around the holidays, is what we call: White Christmas.

Why not go full 64k with battery backed up RAM? It’s even possible to replace ROM area with RAM, so you can load your own custom ROMs.

https://web.archive.org/web/20210224003 ... mories.htm

If you don’t want to soldier you can get this modern external RAM board:

https://www.ebay.co.uk/itm/116017640518

I have several storage options. But if you have an Arduino, you just upload the firmware for TZXduino, and connect the output pin for Ear to the ZX81. That pulses 5V to the ZX81 from an SD card. That works flawlessly. So find anything that can send outputs that pulses from 0V and 5V. It needs to be ...