Many moons ago, I was working at a wind tunnel for aeronautic research. In the first week, when I started on my job, my future colleagues threw a lot of outdated computer stuff into a large dumpster. Only many years later, after I became more aware of old computing technology, I realized what that trash was. Duh! I recently dug through our library and loaned some reports describing the equipment and the software at the time. Besides several HP 2116, ASR-33, Tektronix 40xx, x-y plotters and more, I also read about their first (pre HP) computer, which was used to control data acquisition and postprocessing. It was installed in 1966 and replaced by a HP 2116C in 1972. This was a Pacific Data Systems PDS 1020. It was built into a table and featured an IBM typewriter for printed output and a reader and a punch for papertapes. One report also contained the "listing" of the program, which is a 4-character hexadecimal dump (with unusual hex digits). To give you a "feeling" for the code, here is an example subroutine: 0256 L0LS 5001 0258 525S- L0LS M029 CS7D 2260 L0LA M029 CS7D 0260 L011 3002 L0C3- A26M- CS81 3S5A- 7262- 227C 0268 0000 4500 2000 0500- 3000- 4000- 5500- On bitsavers I found scans of some manuals with the instruction set and encoding. However, these lack complete programs. Therefore, I have scanned and re-typed the original programs from my report in their original form. Now I am thinking about writing a simple simulator to read and execute these programs. The PDS 1020 seems to have been a relatively low cost and hence successful computer, but searching the internet I can find only two machines which seem to be in museums. Maybe a few more have survived in personal collections. #1: https://www.computerhistory.org/collections/catalog/102686768 #2: https://collections.museumsvictoria.com.au/items/397741 Are there more? Are some of them in working order? Is there already a simulator available? Martin