Thanks, I was looking for this since a long time. :)
@backofficeshow
2 жыл бұрын
No problem!
@gregryan7761
3 жыл бұрын
Very nice, thank you for this.
@ncot_tech
4 жыл бұрын
7:16 - when you unplug the composite lead the image appears on the TV before you plug the RF cable in. That thing is radiating so much RF it could probably work sat on top of the TV without any wires :)
@backofficeshow
4 жыл бұрын
I noticed that myself on the playback 😂 I think you are right, could probably plug in a portable TV antenna into it as a transmitting antenna for whole house viewing 😂
@game_whisperer1606
4 жыл бұрын
Nice one Doc. Never knew you could have composite and RF via the same connector. Looking forward to the 16k mod.
@backofficeshow
4 жыл бұрын
I'm just waiting for the parts, hopefully they won't take too long, it would be nice to keep the momentum up on this project
@MrPGT
4 жыл бұрын
@@backofficeshow Momentum? That was back in your crazy one video per day experiment. The randomness was awesome, but the pressure on yourself must have been huge.
@backofficeshow
4 жыл бұрын
I just was motivated to do it. I'm lucky if I motivated to get out of bed the last 6-months so any video is a good video right now 😂
@nickblackburn1903
3 жыл бұрын
"any crt TV you are likely to have will have composite ..." Not mine baby, mine are all late 1970's CRT's Very good video though, thanks!
@MrFlint51
3 жыл бұрын
I did some other stuff too, e.g. a RAM chip piggy backed on to the ROM with select switching triggered by video RAM access. You could program new characters (8x8 pixels) into the RAM to get high res graphics; that one came from a magazine. How about some SRAM with a button cell to save the contents at power off? How about increasing the available RAM with some modern chips? Remember that the Z80 has select lines for In/Out as well as memory access. Would it be possible to construct a Ramdisk as an alternative to cassette storage?
@backofficeshow
3 жыл бұрын
Ewen, let's start with the ram upgrade, that should be a good easy one to start with. Playing with GPIO certainly sounds like a lot of fun, I'll look into that as well
@gingerhippygaming7962
3 жыл бұрын
Nice one I do love the zx81
@backofficeshow
3 жыл бұрын
Keep an eye out for another exciting installment this week 😁
@gingerhippygaming7962
3 жыл бұрын
@@backofficeshow I have a zxpand for mine it's an amazing bit of kit Will look forward to your next video
@backofficeshow
3 жыл бұрын
I'll look out for one
@bazza5699
4 жыл бұрын
good job there doc.. interested to see what you can do with it when its 16k. my first computer was a 16k spectrum
@backofficeshow
4 жыл бұрын
It might consist of: 1) Run a program to see if 16k working 2) Put zx81 into the cupboard of shame 😂😂
@user-mr3mf8lo7y
3 жыл бұрын
Could you please share a link to the video amplifier module you used during the video? Thanks,. (btw, your site having problems to connect to the 'store', ..not working..)
@joegott1627
Жыл бұрын
I noticed that you appear to have not used the second ground on the ZX8-CCB (the one next to where the brown wire connects). In one part of the video (5:58), it appears that this second ground wire is just laying aside resting on the cover for modulator. Is there a reason you did not use the second ground? And is it safe to not use the second ground?
@dolsthoo
Жыл бұрын
The video port needs to be connected to the mod's video out (brown) and ground (black). But in this video the existing video port is used, which is already grounded. So no need to ground it once more.
@MartinFarrell1972
3 жыл бұрын
The ZX81 in HD. I can't get any tv in my house tuned into the zx81. Even an old CRT from the 90's couldn't show a stable picture. Would the mod solve this? The only other problem is the red hot power supply
@backofficeshow
3 жыл бұрын
I would always sure l start by checking the PSU first and if possible the 5v rail on the board.
@MartinFarrell1972
3 жыл бұрын
@@backofficeshow That's beyond me! I don't know anything about boards and soldering. I was going to attempt to upgrade my commodore 16 to 64K. Quite easy to do but the power supply has a loose connection.
@backofficeshow
3 жыл бұрын
I would consider those a pre-requisite to installing any mod. A cheap multimeter could be had for a fiver and plenty of videos on how to use it.
@MrFlint51
4 жыл бұрын
The last mod I made to my ZX81 was a proper keyboard. Could you show us how to do it without destroying the kbd input chip (like I did).
@backofficeshow
4 жыл бұрын
Certainly! I can do that for sure. We would need a suitable keyboard first though 🤔
@MrFlint51
4 жыл бұрын
@@backofficeshow I made mine using click -switches on a breadboard and hand wired the matrix using the circuit diagram. Maybe that's why I fried it
@backofficeshow
4 жыл бұрын
I might have something 🤔🤔🤔
@whoam42a1
4 жыл бұрын
Can you tell me where to obtain the video board ?
@backofficeshow
4 жыл бұрын
I would ask Peter over at zxrenew.co.uk/
@pinkmouse4863
4 жыл бұрын
"I've already loosened the screws on the case" Don't fib, you never tightened them up again, did you? :)
@backofficeshow
4 жыл бұрын
I wish you were right, I'm not that clever, I've removed and replaced the screws at least 6 times today alone 🤫
@ChurchyUK78
4 жыл бұрын
First
@backofficeshow
4 жыл бұрын
That was super quick, were you waiting and hitting refresh? 😂
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