IMSAI 8080 Classic Microcomputer System

Mail List wrote: I'll go one better than this... I'm going to sell my Imsai 8080, but I don't want to ship it. I'd prefer a 'local' buyer to come see the machine and carry it away after verifying it's operational, etc. This Imsai is located in central Massachusetts, about 1 1/2 hour west of Boston. This is not an eBay sale. This is a machine that needs to go to a 'good home', like a list member. The machine... Is a stock Imsai 8080 with its original CPU (C8080A in the gold on white package). It is tested and operational. Cosmetic condition is very good, with only minor scratches to the top cover. All switches are good, and it has a full (22-slot?) set of backplanes installed. The memory... Currently there is 40K of (working) SRAM installed in the following configuration: Two 4K byte SSM (Solid State Music) RAM boards with gold on white ceramic 2102's (soldered in). One 8K Ithaca Audio 1A 1110 Rev B RAM board. One 8K Ithaca Audio RAM board with no revision markings, socketed RAM

One DRC 8K RAM board, no model or revision markings, socketed RAM chips. Two PTCO 4KRA RAM boards (soldered in). One S-100 extender board. The I/O boards... One Tarbell 1011D FDC. One SSM IO-4 board, 2 serial ports, 2 parallel input ports, 2 parallel output ports. Extra stuff not installed in the machine (untested)... One Canada Peripherals CL2400 Real Time Clock. One ThinkerToys Disk Jockey 1. One Compuprisim color video display board (16K DRAM). Three Solid State Music audio synthesizer boards. Known non-functional memory boards... One 8K SRAM board, marked "F. Duston 1977". Two PTCO 4K SRAM boards. One Vector 8800V prototyping board, unused. Peripherals and Software... Two Sugart 8-inch floppy disk drives in an external chassis with power supply. Several boxes of 8-inch floppy disks with CP/M 1.4 and assorted software. While the CP/M disks are included this machine IS NOT running CP/M! The reason being, when I got the machine (from the original builder) the I/O board had been removed, and the DIP switch settings changed. I don't know the correct configuration settings for the BIOS, and I don't currently have enough memory installed to boot all of the CP/M builds (48K being the most common label on the system disks). Documentation... I beleive that all the documentation is present. Many manuals for the Imsai chassis, as well as for the various memory and I/O boards are present. Testing performed... I have run this Imsai and verified the CPU and memory are operational. I have also entered the floppy disk test programs from the Tarbell controller manual and verfied its ability to read and write sectors to drive 0. Also the Tarbell bootstrap works correctly. I have also written simple test routines to send and receive serial data from the console serial port. In short, this thing works just fine. Terms and Conditions... Physically come and see the machine and documentation, and if its state is acceptable, pay cash and carry it away. I'll supply my own box of tissues and try not to cry uncontrollably as you drive away. Once the machine is accepted, there is no warranty and I'm not really able to help the buyer get this machine running CP/M. The Machine's history... This Imsai was built by a former co-worker. He used it to learn programming, experiment with electronic music, and to keep records for his bowling league (from looking at his disk labels anyway). The machine was placed into storage when he went off to college (around the time of the modern PC's introduction). On his return, the machine was well behind the state of the art, and it never returned to service. The machine came to me directly from the closet of his parents' home. As I was bringing the machine up, it suffered a failure of a bridge rectifier diode, and was repaired with new diodes with a more appropriate PIV rating for the application. This repair is not visible. All the power supply capacitors are original, and meet their capacitance and leakage specs. With a rather low number of total operational hours, the interior of the machine is much much cleaner than would be expected of this vintage. I've had the machine for the last 5 years. Reason for Sale... I've wanted an Imsai since reading the ads in Popular Electronics back when I was in Jr. High School. Several years ago I got this machine from its original builder (who did a very reasonable job). In the years that I've owned the machine, I have not found or made the time to get this machine into its proper state, and I'm failing to do it justice. Much of my classic computer time is going into my HP machines, and my Imlac as well. I just have not found the time to conserve this machine properly, I lack the low-level CP/M knowledge needed to build or tweak the existing O/S into a working state, nor do I have another CP/M system to build a CP/M 2.2 disk for it. So in the painful process of focusing my collection and classic computing efforts on my HP 1000's (and Imlac), I'm going to part with my treasured Imsai. Now then, this leaves only one more detail... The Price... $1,250.00 USD. Cash and carry. Location is Leominster MA. Good homes only need apply. Here's your chance to get a 'complete' Imsai system for the price some CPU chassis go for without drives and extras. Skip the eBay rat-race of last minute sniping and get that instant gratification of a simple, direct purchase! Got Blinkenlights? If not, buy a real classic. If this is the Imsai for you, please email me off list at: bshannon(a)tiac.net