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Hi, Is there any differences between in the level 1 roms? I see here there may be at least two versions https://www.trs-80.com/wordpress/zaps-patches-pokes-tips/rom-comparison-page-model-i/ I searched in vain, so would appreciate any insight. Thanks,

Hi, Has anyone had good luck with replacing the power switches on their model 1 or Expansion interface? I've used these: https://www.digikey.com/en/products/detail/c-k/F4UEE/417520 The one I got for my EI has worked great (so far). Unfortunately, I've gotten two for my Model 1 and they both...

Hi everyone, I have a M1 that I've been trying to get working a bit more reliably. The latest issue I'm chasing is a flaky boot issue. The M1 boots intermittently. It is a rev-G board, with relatively few mods. What I've noticed is that when it fails to boot, I get garbage on the screen...

Hi everyone, I'm repairing a model 1 monitor that was damaged in shipping. I now have the display working and adjusted, but am getting rhythmic noise (snowy) distorting the entire screen every second or so. Otherwise, the display is quite readable. This happens with the computer on or...

Anyone have an idea what this button was intended for? Here is how it is wired internally: I checked with a PEEK, and the button is wired to the last row of the keyboard matrix (same as the shift keys), and returns a 16 when pressed (e.g. bit 4). The shift keys are bit 0. As far as can...

I had one of these as a kid, and would like to restore one. Any condition is okay. If anyone has a leads, I'd appreciate it. Thanks! https://en.m.wikipedia.org/wiki/APF_Imagination_Machine

Hi, I recently acquired a TRS-80 model 1 and was inspired by Ian Mavric's FreHD ROM mod supporting switching between the stock level 2 ROM and a modified version supporting autoboot. Before I got a chance to install it, I happened to acquire a second TRS-80 model 1 with some mysterious...

Hi, I have been trying to fix my noisy M4P. After fixing the fan, I was troubled by a high pitch noise that seemed to be oddly load dependent. My first guess was the power supply, but that wasn't it. High pitched noises are hard for me to localize. I finally traced it to the modem board...

Hi, While in lockdown, I've been working on an improved version of my floppy drive switch. I'm happy to report that it is working... TL;DR: I can boot from an external floppy on my model 4P GA, with the boot drive switchable via s/w. Sorry for the long post, skip to the bottom if you want...

I got another model 100 recently and it came with a strange option rom labelled disk+. I assume this is to connect to an external disk (which I don't have). Does anyone recognize it? The call 63012 sequence works as far as I can tell as it updates the menu. Thanks

Hi, I have an ebay rescue 4p that I'm trying to restore. At first power up I get the power light to come on, but nothing else happens. The screen is dark, no activity from the drives. All I hear is a faint buzzing. Upon disassembly I checked the ac in on the power supply and it is good...

Hi Is there a way to boot from the external floppy interface on a model iii? I have a hxc floppy emulator and would like to boot from it without having to swap cables. Preferably, I'd like to be able to switch between booting from the internal and external interfaces. Thanks

Hi, I have an ebay rescue coco3 which I've gotten working again, recapped, 6309 and 2mb... but is somehow missing the feet! This will not do! Anyone know where I can get replacement feet, or have an extra set off they'd like to sell? Thanks,

I know there are lots of threads on this common issue, but I've only read one where it was mentioned that you can take the pots apart. While it looks like I can find these pots new, I wanted to see if I could fix mine properly and permanently. I took some pictures just to show it can be done...

Hi, I have just got my model 3 working with a M3SE and would like to see if my graphics is working. Is there a simple cmd that I can run under ldos that will exercise the card? Hopefully a standalone cmd not a dsk? I haven't yet mastered making a disk yet, so am just ftping files to the...

Anyone know what the strange hack on my floppy drive is about? It appears to be a 7406 piggy backed on some other chip Oddly, my model III seems to have two very different drives as my second drive doesn't have this mod. Thanks!

Hi all, I just aquired a model 100, model 3 and Coco 3. So far I got the M3 working, and it shows a copyright date of 1980 for the basic. Is there a list of rom versions that have been made? Once I get them all working, I'm thinking I'll update the ROMs to the latest (or custom versions)...