________________________________________ From: cctalk [cctalk-bounces at classiccmp.org] on behalf of W2HX via cctalk [cctalk at classiccmp.org] Sent: Tuesday, March 21, 2017 11:49 PM To: General Discussion: On-Topic and Off-Topic Posts (cctalk at classiccmp.org) Subject: booting os/8 Hi folks, I have a PDP-8/e that I've been working on. I have completed construction of AK6DN's RX01/02 emulator. I got to the step tonight where I was trying to boot an OS/8 disk image and nothing was happening. I realized that I do not have the bootstrap diode board in my 8/e so begin the bootstrap triggered by the "SW" switch. Does anyone have the program I can toggle in for the bootloader? What I found is somewhat confusing. Here is a discussion on this topic. https://groups.google.com/forum/#!searchin/alt.sys.pdp8/RX01$20boot|sort:re… It seems one fellow was attempting to edit/improve the bootloader of another fellow. I was wondering if anyone has distilled this into something simple. At the moment, I care only about booting from RX01-Disk0. Any pointers greatly appreciated. Thanks Eugene W2HX ___________________________________________ Well, I am sure glad someone posted this. I had never heard of the work done by AK6DN and have considered looking into such a project in the past. So, has anyone looked at someting sililar for RL drives? bill

I felt the poor 8085 CPU was under represented and my Tandy M100 was lonely so I added a NEC PC-8201A. The 8201 needed some help to get it going. Things like the foam around the LCD to front bezel was turning to powder and regardless of the battery used it was faulting on low volts (blank screen) plus the internal NiCd was dead and starting to leak. Attacking the power supply corrected the /LPS (low power shutdown) fault due to a bad transistor and now it works well. Next step is to fill the two banks of ram as it only had the factory 16K and can carry 96k. The first software project is to get to near the bare metal. That is a way to load machine language programs and run them where the first code will be a simple Monitor. At some later point I'd like to mod it so the load and store (cload cstore in basic) insted of using audio cassette tape will be to CF or SD mass storage. I may have to resource the rom to to do that or go from scratch. I haven't decided on an OS or start from scratch CP/M is a likely candidate as porting it to 8085 is done deal and adding modern mass storage of any sort is easy (BIOS). The CP/M route opens a door to a great deal of software that will run on 8085 as not all that much required the Z80. The only requirement is 64K of ram from 0000H and the as built memory management can do that. Allison