CP/M on the Altair 8800 without a Floppy Controller or Disk Drive

[@oak_meadow9533]

boy does this bring back great memories! I was living in Jester West dorm at University of Texas at Austin; rm 365 and a friend of mine lived across the hall. He owned an Altair comp and a teletype to communicate with it. This was 1974-75; what a great time to be alive. I went on to minor in computer science and worked in many mainframe computer centers. IBM usually had an entire floor of a basement with raised floors and forced air conditioning thru the equipment to keep everything cool. I watched as system 360 was updated to system 370.... The 100MByte hard disk drives were updated about every 5 years ; I remember the first 286 ; 386, 486; and pentium desktop units replaced the IBM mainframes. (My best friend's dad bid on and bought an entire mainframe sys 370 with line printer (22 pages per minute 132col paper. - SO LOUD) and tape drive and 16 gig hard drive, etc for $5500.00! They built a building on their ranch for it. Amazing. By the time 1990 came along it was easy to afford a home computer. Hahaha.

[@TruthWielders]

We used a audio tape recorder (single track) to store the memory and load it back up, reels or cassette or 8 tracks (more tracks more saves). The signal comes through the RS-232's data pin and sounds like the noise you hear when a modem is connecting. I don't remember how was the tape bootstrapped though when the computer was turned on or reset. It was either the 88-ACR or my father built his own tape serial interface, either way he ended up using the first basic implementation from B. Gates before they started Microsoft.

[@user-nd8zh3ir7v]

awesome, thanks for the great video and explanation!

[@akamadman203]

To note the 2sio board is yes for sale but is now an assembly kit you are sold the controllers, oscillator, rom and board itself.

[@Dinnye01]

It would be really awesome if you shown a few programs beyond the OS running on these.

[@demorcef]

Please start selling Altair Clone Computer again!

[@computeraidedworld1148]

What if you have a different serial card, is the second connector another serial port?

[@LaserFur]

The FTDI 2232 will also run at 3M baud.

[@paulstubbs7678]

Nice, it wouldn't be hard to graft this over to a single board computer that has only two serial ports and nothing else. Another twist could be to make a serial floppy server that runs on an Arduino and stores the images on a USB stick, that way the serial floppy server could be a little box sitting atop the Altair - no PC required.

[@charlesspringer4709]

I liked FIG-Forth one these and IMSAI and I have a no-name and 8" drives that came with it. Also OSI 6502 with 8" drives and huge card cage.

[@kevincozens6837]

What a brilliant idea to use a spare serial port to act as a floppy drive. Is he source for the improved BIOS which provides a 40% performance increase available somewhere for those who are running CP/M? Would that BIOS code also be usable with CP/M 3?

[@deramp5113]

Here is a link to the fast CP/M 2.2 BIOS for the Altair: deramp.com/downloads/altair/software/8_inch_floppy/CPM/CPM%202.2/CPM%202.2B/

[@deramp5113]

A fast CP/M 3 BIOS for the Altair can be found here: deramp.com/downloads/altair/software/8_inch_floppy/CPM/CPM%203.0/

[@superslammer]

Have you ported your disk server to linux? It would be nice to be able to run that off a raspberry pi.

[@michaelstoliker971]

2nd this question.

[@deramp5113]

Another hobbyist created a Linux version of the server a few years back. See github.com/deltecent/fdc-sds. I'm asking him to add the slower baud rates to his implementation to support this project. He also has a GUI for it. I'll find out more.

[@thunderc4s]

Can this also possibly work with an Exidy Sorcerer Z80 based computer ?

[@yorkan213swd6]

What about a Harddisk interface ?

[@argonwheatbelly637]

As long as you can PIP files around, then I'm game. 😎