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Hi, I am just now seeing this post... We have created a parts list for the MTM Scientific, Inc PC-Retro Kit. (We sell the bare PCB on our website.) We also occasionally have a few complete kits...

Hi, I wanted to provide an update on the Instruction Set for my homebrew computer. The most significant change I made was to make the ALU functions completely programmable. That gives 16 logical and...

Thank you everyone for your thoughts and ideas on this topic. I have spent the past several days reading, thinking and exploring the suggestions.

The elephant in the room is the ALU. Here I have a...

Hi, I have built a homebrew computer using TTL IC's according to the architecture described by Eckert in his paper "Microprogrammed Versus Hardwired Control Units: How Computers Really Work". The...

I just now noticed a question has been posted about this rocket altitude predictor program... The program and method of calculation is described in detail in Chapter 8 of the 7th Edition of the book...

Thank you everyone for your ideas and comments! As suggested, I looked at the old newsletters from the UK ACC. There is a homebrew design using the 74181 ALU in Volume 3, Issue 4. There really was...

Hi, I am building a simple computer for fun that uses the 74181 Arithmetic Logic Units. These ALUs were the basis of some of the older vintage computer designs. I am trying to identify a Register...

Hello, Thank you everyone for pointing me to some very useful resources! As Dwight mentioned, the links above have some especially useful information about interfacing RAM and ROM memory to the RTX...

Hi, I recently was able to obtain 3 pieces of the Harris RTX-2000 CPU. This CPU has been used on numerous spacecraft by NASA, and in various embedded or development cards for computers in the early...

The system development boards from Intel have alot of resources on the web if you start to dig. While I was doing just that for a board I picked up, I found this website where the fellow has...

Hi, Lately I have been toying with the idea of building a stack machine computer. This would require a CPU that has more than the rudimentary stack operations of Push, Pop, etc. My research has led...

Thank You Al for posting those links! Extremely useful. If you are reading this and have any present/future interest in running UCSD P-System on an IBM 5150 I definitely suggest grabbing both items...

I have discovered a few tricks working with various UCSD disk images. Some images have an extension ".IMD". I have found that these images can be converted to a binary format by using a program in...

Those manuals are absolutely amazing! Definitely will get me going while I continue the search for the IBM. Thank you so much. Michael

Hello, I have searched extensively for a copy of the IBM manual(s) for the UCSD P-System. (This was an alternative operating system to DOS and CP/M for the original 5150 PC). Does anyone have a copy,...

I apologize for resurrecting this old thread, but the original post is short, and the problem was not resolved. The OP could not test his 8087 FPU using some simple instructions compiled using debug....

I burned a ROM and ran the diagnostic code in a stock IBM 5150 PC. Attached is a photo of the output that is displayed on the screen. Thank you for making this project available to the forum! ...

Here is a screenshot of Ruud's Diagnostic ROM working on 5150 PC hardware. This is a stock motherboard with MDA display adapter. I doubled the file using a Hex Editor to 16K, and burnt it to a 27128...

Hi, I just wanted to do a quick followup on this thread, in case anyone finds it in the future doing a search. Despite repeated efforts to address the shared memory in the 16bit 3C503 network card I...

Hi,

The PC-Retro was first offered in 2012 by MTM Scientific, Inc after a long period of development with the valuable help of many regular contributors on this forum. Since the initial offering...

Hi, I have a 3C503-16-TP ISA Network Card (Etherlink II/16TP) and I am trying to find and use the shared memory space on the card in a 5150 PC. The card has a 16K boot ROM socket with selectable...

Thank you everyone for your help and comments. I did another FTP upload to fix the truncated file. The manual on WinworldPC looks like a winner for understanding how to pull the legacy data off this...

Hi, I recently purchase an IBM 5161 Expansion Unit, XT Computer, and Cable. To my great surprise the system has booted with relative ease, except for a blown capacitor on the CGA card. I've booted...

Hi, Thank you everyone for you comments and input. I have created a webpage to describe the MIOS project. It is available here:

http://www.mtmscientific.com/mios.html

Hi, I have a 8 bit ISA clock card manufactured by HYPER MICRO, called the HYPER CLOCK. This card caught my eye for the simplicity of layout. The support circuitry for the MM58167 RTC chip appears to...