Introduction and IBM 1130 replica project

Dave wrote: Richards excellent work was what first got me involved with this - after watching his talk and contacting him, he shared his code and expertise to allow me to create a copy of his emulator. It inspired me to learn hardware design and electronics and to aim for my project. Richard designed his machine by designing hardware that would match the Functional Characteristics manual, analogous to how Amdahl designed an IBM compatible system by adhering to the Principles of Operations but adopting their own unique design within the machine. He did not have a goal to emulate the hardware console functions such as Single Step, Single Memory Cycle, Interrupt Run, Load, and so forth. Since I first got hands on experience with computers on an 1130, learning by using those controls and watching what my code was causing to happen, I wanted to recreate to that level. My machine is built to map almost exactly onto the logic gates of the 1130, as I used the ALDs (automated logic diagrams) to recreate the system. It is designed to run at the same speed as the physical 1130. It is therefore a cycle by cycle faithful recreation, allowing someone to see what changes when releasing the Start key in Single Step mode at cycle T4 of instruction phase E1, which is phase B of the clock. Certain conditions change or actions take place on specific phases of those cycles - this recreates them. I also mapped all the hardware adapter logic faithfully and built hardware to emulate all the signals that came into the 1130 from the peripherals. As a final step, I adapt real hardware I have, an Electronic Typewriter 50 (selectric ball type machine), to link to my hardware emulation so that it behaves the same. My keyboard is a photocell driven partially mechanical unit from a keypunch of the era, interfaced to link to the 1130 adapter circuits and present the exact signals that would come from the real 1130 keyboard hardware. I built the display light pedestal above the console printer to scale, as another example of my obsessiveness. My aim is to replicate the experience of running an 1130 hands on. This certainly is no denigration of the emulator built by Richard Stofer - it provides higher performance than a real 1130 and from a programmers standpoint is a truly faithful replica. For most people, that is all the recreation they want. Beyond that, there are software simulators such as the one hosted by Brian Knittel at http://www.ibm1130.org with a full set of 1130 software at the same site - highly recommended. This project has allowed me to meet a number of great people who have offered advice, aid and a supportive ear as I toiled away - I try to credit them all in my blog, but it is possible I haven't mentioned all of them. I am also indebted to Al Kossow and the Bitsavers archive for availability of ALDs and other documentation sufficient to produce this hardware level recreation. Sounds like you are having some fun yourself. Hope it is going well. > I guess we are all bonded by an appreciation of early technology machines that were formative for us. Carl ________________________________ This e-mail message, including any attachments, is for the sole use of the person to whom it has been sent, and may contain information that is confidential or legally protected. If you are not the intended recipient or have received this message in error, you are not authorized to copy, distribute, or otherwise use this message or its attachments. Please notify the sender immediately by return e-mail and permanently delete this message and any attachments. Gartner makes no warranty that this e-mail is error or virus free.