12 April 2026
(SKIP AHEAD TO BUNDLE DOCUMENTATION)
These are "required reading" documents for the Friendly fZ80. MP/M is sophisticated enough, and sufficiently different from CP/M, that I strongly recommend at least skimming through the MP/M Users Guide. MP/M is surprisingly rich and complex relative to CP/M.
Note also that all Digital Research manuals were distributed as 8.5" x 11" printed and stapled booklets; the per-page textual density is low, and they're much more readable printed than online. These PDFs exist because amateurs spent the effort to scan, edit and produce PDFs. Some of the PDFs contain formatting errors, due to OCR technology available at that time it was scanned.
This is an electronic copy of the printed manual provided with every machine.
Here is the Digital Research CPM Operator's Manual in two forms: a TRUNCATED version, only the crucial 95 pages of built-in and basic utilities, and the full Operating Manual, some 300+ pages that includes the DDT, ED, and other manuals. Look before you print.
Digital Research MP/M II 2.1 manuals; you really want the User's Guide, it is invaluable.
Other Digital Research CP/M manuals. Some of these smaller manuals (ED, DDT) are contained in the CPM 2 Operating Manual full version, above.
Digital Research's TEX text formatter, used to make many of their manuals or maybe all of them; it's a "roff"-like thing where embedded text codes and keywords dictate how the document is to be formatted.
Digital Research's CP/NET, a client/server setup for diskless CP/M clients and MP/M server.
These Phoenix Software Assoc. manuals were scanned from a printed set from 1980 that I personally kept from my time at CSSN (Computer Service Systems Network, Boston MA), intended to be delivered with every CSSN System 1000. They were scanned by Kevin Driscoll and massaged into individual manuals by me.
PSA arose from the ashes of TDL/Xitan; PASM and PLINK are slight upgrades from TDL'x ZASM and LINK (Cromemco's ZASM is different). PASM and TDL ZASM use TDL's Z80 opcode mnemonics, an extention of the Intel 8080 instruction set but including the then-new Z80 opcodes. (As opposed to Zilog's fake orthogonality, not actually expressed in the instruction set.)
Here are the TDL (Technical Design Labs) versions. The ZASM.COM in the PSA-TDL-PASM-PLINK bundle is version 2.21, so the first manual below is the correct one; the 1976 manual is included for completeness only.
PASM is my favorite assembler; PLINK II does overlays very nicely.
These are not pertinent to fZ80. PDOS was PSA's expanded/extended CP/M operating system clone, with better hacks for use of USER numbers, time and date stamps, and other fancy things with directories. It could read and write CP/M diskettes. As far as I know this is the only copy of PDOS documentation on the net.
These are not pertinent to fZ80, but I can't think of a better place to store them. BackUp was a tape backup system modelled after some gigantic IBM tape system, with savesets, multi-tape support, time stamps, comments, and a scripting language. I wrote it in MAC.COM I think.
Bug/microBug is PSA's debugger meant for boot-ROM use. TextEditor I have no recollection of (is this PMATE?).
These are manuals found for the software in the distribution bundles.