Dr. Scott M. Baker's Flash and RAM Board Is a Major Upgrade for Your Vintage HP 9000 Microcomputer
Based on earlier work by Dominique Berget, this add-in board offers a copy of BASIC in ROM plus additional RAM for Series 200/300 systems.
Maker and vintage computing enthusiast Dr. Scott M. Baker has been hard at work on an upgrade for Hewlett-Packard's HP 9000 family of microcomputers: Adding flash storage with a copy of BASIC and a chunk of RAM on a simple slot-in board.
First released in 1984, the HP 9000 family of microcomputers covered workstation and server ranges and started with the 200 Series. The majority of the early units were sold to run standalone applications, while a Basic Workstation — or rival Pascal 3.1 Workstation — operating system gave them on-board programming capabilities.
These operating systems, however, were designed to run in RAM - reducing the amount of memory available for your own programs. The solution: Add-in ROM boards, such as the Fort Collins Systems' 98603A BASIC 4.0 ROM. "[I] found references that Dominique Berget had documented the schematics and reverse engineered and reproduced the BASIC 4.0 board," Baker explains of the origins of his modern-day recreation.
"I contacted Dominique and asked him a few emails — he sells completed boards, but not kits or bare [PCB] boards. He provided me with some additional schematics, links to the ROM images, and advice on creating my own board. It seemed simple enough to do so, so I set out to design and fabricate my own boards. While the first one more-or-less worked, it took me about four revisions to finally get the design to the point I was happy with it."
The result is a new add-in, designed for the DIO Bus and compatible with the HP 9000 200 Series and 300 Series systems. Two flash ROMs provide a copy of BASIC — or, technically, any other operating system you'd care to write or port to the systems — while RAM chips expand the memory available to the system. A programmable logic device provides glue logic to interface with the DIO bus, while two mounting toggles at the top of the PCB were "scavenged from a 256k HP RAM board."
Baker's full write-up, complete with a schematic of the board, is available on his website; he has not yet published the design to GitHub, but says it is on the to-do list for the "work in progress" project.