Technical Documents

TECH REFERENCES

  • PC-8200 Technical Notes
  • Hardware port mappings, Description of ROM routines, Math routines, Information for Option-ROM, Machine-code file handling routines, BASIC program file handling routines, Internal structure of the PC-8201A RAM file system, and tape format.

  • NEC PC-8201A Service Manual w/Schematics
  • The NEC PC-8201A Service manual is a complete reference for servicing the hardware of the machine, and includes: Functional Specifications (Logical, Physical, I/O, Software interface, Human interface, Performance, Accessories), Disassembly/Reassembly instructions (Cover, LCD, Keyboard, Power Supply board, Main board), RAM/ROM insertion, Battery installation, Operation tests (Power supply, CPU, CPU Clock, Calendar clock, LCD, SIO1/SIO2/RS-232C ports, BCR port, Parallel port, CMT interface, Speaker, Keyboard), Troubleshooting abnormal operation, IC removal, Parts lists, Circuit diagrams, Schematics.

  • NEC PC-8201A Technical Reference
  • Memory map, how to use 2nd ROM, how to use 2nd/3rd RAM banks, Understanding the RAM file concept, Directory structure & configuration, RAM organization (bookkeeping area, VRAM area for LCD, BIOS bookkeeping, FCB), RAM File handling, Hardware specs for: LCD Interface, Keyboard interface, CMT interface, Serial interface, Barcode interface, Parallel interface, and finally the System bus and memory control circuitry. It is a *must have* if you're a serious programmer for the NEC.

  • NEC PC-8300 Technical Reference
  • Here's the same document for the 8300, with a few additions. The 8300 can use a 128K ROM and bank switch between four 32K images contained inside. The additional circuitry to do this is not present in the 8201A. Also, the 8300 had support for an optional internal modem.

MEMORY MAPS

PROGRAMMING

  • Designing Cross-Compatible programs for the Model 100 & NECs
  • It is actually fairly simple to design your program from the ground up so it can run unmodified between the Tandy and NEC models of notebooks. You reach the widest audience this way, plus it adds an interesting challenge to your development project. In the Windows world, you, the consumer, certainly wouldn't tolerate a situation where a Windows program was specific to an IBM computer and required changes to run on your Dell! :-) Think about embracing the idea of cross-compatible software development for the "Model T" machines.

  • Converting Model 100 programs to work on NECs
  • Here are the main issues of concern when trying to convert a program written for the Model 100for use on the NECs. With all of the software out there available for the Model 100, this information can be quite beneficial.

HARDWARE

  • SIO1 / SIO2 / RS-232C port information
  • Here you'll find pinouts and I/O port control information that let you use those extra ports on the back of your NEC.

  • NEC PC-8300 can emulate the 8201A!
  • How do you switch between the "8201" emulation mode on the NEC PC-8300? Find the info here!

  • Converting the NEC battery pack for NiCad's
  • By soldering in a jumper and a resister into the battery pack, you've just converted it into a NiCad cartridge which will charge four NiCad's off of the 8.5V power supply. You're free from buying those pesky alkaline AA's forever.

  • Creating your own 32K memory module!
  • Here are plans for creating your own 8K and 32K memory modules from some very inexpensive chips. If you're good with a soldering iron, this might be the ticket for expanding your PC-8201's banks of memory. (Not applicable to the NEC PC-8300 - It already comes with a full 64K which is the maximum capacity internally.)

  • Tandy Portable Disk Drive Cable Revealed
  • You have a Tandy Portable Disk Drive (TPDD or TPDD2), but no cable...or a cable that is broken. What do you do? Thanks to Marty Goodman, you can build your own cable with a little ambition.

  • NEC Y2K Fix
  • If you have access to an EPROM programmer, you'll be able to implement a cosmetic Y2K "fix" for your NEC PC-8201 or 8300. There's just a couple of ROM locations that need to be patched, and you'll never have to see a "19xx" date on the system menu again!

  • Model 100 Y2K Fix
  • The same cosmetic fix is possible on the Model 100 as well, however you'll also need to be handy with a soldering iron. I followed these same instructions and it took me about three hours from start to finish. Thanks to William McCrosky who originally reported this successful hardware solution. (PDF format, 200k)

MISC.

  • Getting downloaded files into your NEC
  • . . . The HOT Setup: The most flexible option for loading & saving files between your NEC and your DOS or Windows Desktop PC would be the NADSBox & TS-DOS combination. The NADSBox device is available for purchase from Club 100. In the absense of a NADSBox, another option would be to use the DESKLINK & TS-DOS combination. Plus, there always is the old fashioned terminal program to terminal program connection that you can set up for manual uploads & downloads between computers. Information about both all of these methods is just a click away.

  • How I used 22DISK to read my CP/M PICDisks
  • The PICDisk was one of the specialized disk-drive systems available for Model T computers. Not just a disk drive, it literally turned your Model 100 or NEC into a full blown CP/M computer. Unfortunately, mine was stolen way back in 1990, and I had a ton of disks that I could no longer read. Here's how I "resurrected a dinosaur" and regained access to those CP/M disks, using software called 22DISK. If you have old CP/M disks and you want to read them from a Windows machine, 22DISK is your tool!

  • Archive of NEC PC-8401/8500 "Starlet" Discussions from GEnie
  • This is the first of (hopefully) many bits of technical information that I will post on this web site. You might find answers to questions about the Starlet machines within this document.





The Original Laptop Computer . . . 1983

Copyright 1999-2018 by Gary J. Weber. All Rights Reserved.
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