General info on HP2000/1000 lineage..

Someone just asked me... I thought my response might be of interest to others, so here's the scoop... The oldest systems in the "1000" series are the M series. They consisted of the 21mx 2112a, 21mx 2108a, and the 21mx 2105a. Later HP introduced the E series with the new 21mxe 2113a and 21mxe 2109a boxes. The E series did not replace the M series though. Then there was a major revision to the power supplies used in the cpu which was indicated by the B version (21mx 2112a became 21mxe 2112b, 21mxa 2108a became 21mx 2108b, 21mxe 2113a went to 21mxe 2113b, and 21mxe 2109a went to 21mxe 2109b). The 21mx 2105a stayed 21mx 2105a though. Finally there was the introduction of the F series with the 1000F 2117f and the 1000F 2111f. When the F series was introduced, all the systems became known as 1000's model such and such, with different designations. So finally there was the HP1000 F series 2117F, the HP1000 F series 2111F, the 21mxe 2113b became the 1000E 2113e, the 21mxe 2109b became the 1000E 2109e, the 21mxe 2112b became 1000M 2112m, and the 21mx 2105a finally changed to 1000M 2105a. More to the point, most of the upgrades along the way in a given branch were related to the power supply, the addition of more instructions to the instruction set (most related to better memory management), and faster memory boards. The HP 2000 systems did not designate a particular cpu. HP2000 or access, 2000a, 2000b, 2000c, 2000c', 2000e, 2000F (option 200/205 or 210/215), and the third party (NON-HP) 2000G designated a particular combination of peripherals. The hp2000 family generally used the pre-M series 2114 or 2116 cpu's. Later the 2100A and 2100S cpu's were used. Finally, even though HP still used the 2100 cpu's, many customers switched over to the 21mx 2108 and 21mx 2112 from the M series because they were slightly faster and used the new semiconductor memory. Few did setup HP2000 on the E series because they were faster enough to introduce time dependent problems in the TSB code. Generally the HP2000 designation meant the system was running TSB (Timeshare BASIC) which is my particular target of collecting since it was the first computer system I ever learned. If the same hardware was running DOS/RTE, etc. is was called an HP 1000. Hope this helps! Jay West