Spectrum +2 - no video or audio

For experts to discuss very technical stuff and newbies to ask why the Spectrum they bought off ebay doesn't work.
Post Reply
mthomason
Drutt
Posts: 9
Joined: Fri Mar 20, 2020 8:00 pm

Re: Spectrum +2 - no video or audio

Post by mthomason »

Ast A. Moore wrote: Sun Mar 29, 2020 10:56 pm Hey, glad you were able to sort it out!
Thanks :D

And now I have, it's time for me to think forwards to what I can *add* to it ;) I'm already contemplating how to get it onto wifi via the serial port, either via an ESP8266 or a Pi Zero W. Will write that up if/when I get it working (I know others have, but half the fun is figuring out my own way ;) )
User avatar
1024MAK
Bugaboo
Posts: 3123
Joined: Wed Nov 15, 2017 2:52 pm
Location: Sunny Somerset in the U.K. in Europe

Re: Spectrum +2 - no video or audio

Post by 1024MAK »

Keep in mind the serial port has to use the Z80 to do the parallel to serial / serial to parallel conversion and bit bash the port, as there is no UART chip. Just a simple input/output port and voltage level converter chips.

This is fine for attaching relatively slow devices like printers, or uploading/downloading files to/from a PC where the data flow is mostly all in one direction and not much else needs the processing power of the Z80 at the same time. But less than ideal for more demanding applications.

In any event, have fun and good luck :D

Mark
:!: Standby alert :!:
“There are four lights!”
Step up to red alert. Sir, are you absolutely sure? It does mean changing the bulb :dance
Looking forward to summer later in the year.
mthomason
Drutt
Posts: 9
Joined: Fri Mar 20, 2020 8:00 pm

Re: Spectrum +2 - no video or audio

Post by mthomason »

1024MAK wrote: Mon Mar 30, 2020 2:27 pm This is fine for attaching relatively slow devices like printers, or uploading/downloading files to/from a PC where the data flow is mostly all in one direction and not much else needs the processing power of the Z80 at the same time. But less than ideal for more demanding applications.
Eep, thanks! For now I'm thinking just a simple downloader that connects to an ESP8266 over serial, tells it to connect to a wifi network, Then does an HTTP download of a specified URL. So hopefully that'll not tax it too much!

I really want to start tinkering a little with the Z80 bus at some point, so maybe putting a real UART on there would be a good project for me next :D

- Matt
Post Reply