TRS 80 Model 100 BIOS Problem

[RHopple]

Hello all, this is my first post so here goes.

I recently acquired a TRS 80 Model 100 from a garage sale, and there is a problem with the BIOS chip: it didn't come with one. The previous owner must have taken it out for some reason I cannot comprehend. I was wondering if there was anyone who knew what I could do to get a new one, aside from buying another Model 100.

Thank you all!

 

[Agent Orange]

Hello all, this is my first post so here goes.

I recently acquired a TRS 80 Model 100 from a garage sale, and there is a problem with the BIOS chip: it didn't come with one. The previous owner must have taken it out for some reason I cannot comprehend. I was wondering if there was anyone who knew what I could do to get a new one, aside from buying another Model 100.

Thank you all!

Welcome to the forum. How do you know it's missing the BIOS chip? Does it power on? I've had a 100 since about 1985 and have never once had the occasion to fool with the BIOS. Maybe you're confusing the BIOS with the empty accessory ROM socket?

 

[RHopple]

I know this because I opened it up and the BIOS is missing. All the RAM sockets are filled with 8K, except the far left, totaling 24k. Also, both the main ROM socket and the accessory socket are empty.

 

[Agent Orange]

I know this because I opened it up and the BIOS is missing. All the RAM sockets are filled with 8K, except the far left, totaling 24k. Also, both the main ROM socket and the accessory socket are empty.

I can understand your frustration. As far as I know, there is no BIOS, per se, in the Model 100. Everything is in ROM. Check the following out and tell us exactly what components you are missing.

http://www.classiccmp.org/dunfield/kyocera/m100tref.pdf

 

[MikeS]

Hello all, this is my first post so here goes.

I recently acquired a TRS 80 Model 100 from a garage sale, and there is a problem with the BIOS chip: it didn't come with one. The previous owner must have taken it out for some reason I cannot comprehend. I was wondering if there was anyone who knew what I could do to get a new one, aside from buying another Model 100.

Thank you all!

They used two different types of ROM chip: If the M100 is older than Oct. /83 you will need a small adapter PCB to use a JEDEC standard EPROM; if it's newer then all you need is the EPROM. Since you're replacing it anyway, there are a couple of things you can upgrade while you're at it if you wish (e.g. Y2K) and you can also integrate one of the Option ROMs (e.g. put the TS-DOS transfer program in ROM).

Send me your serial number and address in a PM and I'll see what I can do for you; if you've already got it open then the PCB number would be even better.
PLX110CH1X - Old type
PLX110EH1X - New type

mike

 

[RHopple]

Sorry for calling it "BIOS" instead of "ROM". Guess I'm not a computer genius...