Updated 2018–10–08 A demo for the IBM PCjr by Pungas de Villa Martelli. It was presented at Flashparty 2018 and won the Demo category. Requirements An IBM PCjr with at least 64k RAM. Download Source code: https://github.com/ricardoquesada/64k-ought-to-be-enough Binary: pvm-64ko.zip (does not run on emulators) Technical description The demo is divided in the boot loader and demo 3 parts ...
It’s well-known that you should measure the performance of your code, and not rely only on the opcode’s “cycle counts”. But how fast is an IBM PC 5150 compared to a PCjr ? or to a Tandy 1000? or how fast is the Tandy 1000 HX in fast mode (7.16Mhz) compared to the slow mode (4.77Mhz) ? Or how fast is a nop compared to a cwd ? I created a test ( perf.asm) that measures the performance of different opcodes and run it on different Intel 8088 machines. I run the test multiple times just to make sure the results were stable enough. All interrupts were disabled, except the Timer (of course). And on the PCjr the NMI is disabled as well. Without further ado, here are the results: Intel 8088 opcodes performance
IBM PCjr zero-day data-destroy vulnerability (AKA: Joykill).
The IBM PCjr BIOS is very well documented in the IBM PCjr Technical Reference manual (a must read for every PCjr developer). The only problem is that navigating that code is not easy. It has all the problems from scanned books: the fonts don’t look good no hyper-links and difficult to search So I dumped the BIOS and started analyzing it with IDA Pro - Free version. I added some of the original comments from the Technical Reference manual, and added some comments of my own. ...
Happy new year! We ( PVM) ported our Tandy 64 intro (originally designed for the Tandy 1000HX) to the IBM PCjr. Requirements: IBM PCjr. with 256k RAM Download: Binary: tandy64jr.zip Source code: https://github.com/c64scene-ar/tandy64/tree/ibm_pcjr Worth mentioning: Runs flicker-free Stable raster-bar, without garbage (world-first?)