most recent 30 from retrocomputing.stackexchange.com
everyone, I'm working on a new CPU Instruction Set Architecture inspired heavily by the DEC Alpha architecture, with the eventual goal of implementing it as an actual silicon chip. One thing I'm trying to avoid is simply making "Alpha with some new instructions." I'd like to understand which parts of Alpha were genuinely excellent architectural decisions, which were mainly products of the…
According to https://wiki.osdev.org/Memory_Map_(x86) , the conventional memory starts at 50:0. So it makes sense to load at that address when you have little memory. I also read on some website that the area between 50:0 and 60:0 was the DOS Communication area? What is this?
What is a video and book 📖 on the history of Linux distributions? Who is an expert on the history of Linux? There are many good YouTube channels on the history of electronics (like Tech District ), so I'm wondering if there's a similar channel or video on the history of Linux distributions. The "family tree" of Linux distros is insanely complex:
I'm using the Basilisk II (68k Macintosh) emulator with MacOS 7.0 and 8.0. File system sharing (between host and guest) works fine with 8.0 but I also want to use it with 7.0. According to the manual, to use file system sharing with MacOS 7.0 or 7.1, you have to install the "File System Manager" extension in the guest operating system. (Newer MacOS versions do not require the extension.) Is there…
While I have read that the i487SX contained a full i486DX implementation and would overtake the main CPU (and even work on its own, without a slotted-in 486, as both the FPU coprocessor and the main CPU according to CPU World), and have seen ( such as on the Vogons board ) dual-486 systems, I'm left to imagine that there could theoretically be a system that would have an independently running…
I have Borland Turbo Assembler 3.1 (TASM) on MS-DOS and would like to display the current location ( $ ) during assembly time. Something like this: IF ($ - boot_jump) NE 3 DISPLAY "BOOTSECT.ASM: BPB started at wrong offset: Was $ not 3" .ERR ENDIF This doesn't work though, it displays a literal $ sign. I couldn't find a user manual for TASM 3.1, but neither the TASM 4 nor 5 manuals show any kind…
My retro computer collection is expanding. I have been keeping track of things in my head. Well, thats being generous. I have a general idea of what I have. I did a quick search, but didnt find anything specific for retro computer collecting. There are various software packages/websites designed for general collecting or something else entirely, which can be customized. However, I was wondering if…
Sector 0 of MS-DOS formatted disks generally start with a relative JMP instruction usually followed by NOP (e.g., EB 3C 90 ), and end with the magic number 55 AA in bytes 511 and 512. But now I wonder: Was there any kind of "Boot sector" for non-bootable disks? So that if I have my BIOS Boot order set to "A:,C:" and have a disk in the drive, the BIOS will boot from the hard drive instead? I'm…
During agent-facilitated porting of Unix V7 to the BESM-6 architecture sergev@GitHub has found out that the fgrep tool had an OOB bug in its Aho-Corasick algorithm implementation, resulting in silently missing valid matches. A small example, produced by an online X86 port of Unix V7 is mem = 14016512 # cat > patterns bd debdb ebb # echo debd | fgrep -f patterns # cat > good bd debdb # echo debd |…
I'm reading the new Terminal Graphic Characters introduced in Unicode 17 , particularly the entries in the symbols for legacy terminal graphic characters . For example: U+1CEBA FRAGILE SYMBOL → U+1F377 🍷 U+1CEBB OFFICE BUILDING SYMBOL → U+1F3E2 🏢 U+1CEBC TREE SYMBOL → U+1F333 🌳 U+1CEBD APPLE SYMBOL → U+1F34E 🍎 → U+1F34F 🍏 U+1CEBE CHERRY SYMBOL → U+1F352 🍒 U+1CEBF STRAWBERRY SYMBOL → U+1F353…
I just got a Commodore 64 Ultimate from the original retailer. There is a No Joystick Read Me!.txt file in the Games directory of the disk that came with it. It says that on the C64 Ultimate we can enable emulating Joysticks via WASM keys via the Joysticks & Controllers menu. However, when I navigate to this menu the Joystick Input option is grayed out and locked to Normal . I can change other…
I recently received a Macintosh 16" Color Display. I went to plug it in to test it and it the power cable wouldnt plug into the pins. The outer part of the connector - the black rectangle is solidly attached to the outer housing. However, the 3 power pins do not seem to be connected to it anymore. I can put my finger in the hole (red rectangle) and the piece where the power pins are connected to…
I have been learning more about PlayStation 2 emulation and noticed that many PS2 emulators still require a BIOS file to achieve accurate emulation. From a technical perspective, what role does the BIOS play in the PS2 boot process, and why can't an emulator simply replace it entirely with its own code? I'm also interested in the historical side of this. Were there attempts to create open-source…
In his 2020 article on LabVIEW history in the Proceedings of the ACM on Programming Languages , LabVIEW's lead developer Jeff Kodosky writes ( PDF page 28 ): Shortly after we released LabVIEW 2, Microsoft released Windows 3.1, which was still just a 16-bit OS but it could run on a 32-bit capable 386 processor. Appendix E of their documentation described a mechanism by which a 32-bit application…
Episode 2 of the Italian 1992 TV mini-series " Il ragazzo dal kimono d'oro " ( IMDB ) shows some word processor. A screen is visible at minute 16:02 : The computer, it's supposed to run on, is shown at minute 16:08 , 17:17 and 17:48 , but always sideways:
Does anyone know how to get the TVGA9000C ISA video card to enable its registers without running POST procedure by executing the BIOS ROM? I want to use a Trident video card in a custom 8-bit system with an ISA compatible bus interface, but without an x86 processor, and writing an x86 emulator just to execute the TVGA9000C BIOS ROM is too complex, so I want to replicate the setup procedure in…
I'm planning to write a BIOS-based bootloader for PC systems already running DOS (MS-DOS, IBM PC DOS, FreeDOS, DR-DOS, EDR-DOS or SvarDOS). The bootloader will check that it is running in real mode, load a kernel image file to memory using DOS int 21h functions, restore interrupt vectors to BIOS defaults, explicitly reset some hardware (such as the PIC, the floppy controller, the HDD controller…
I'm seeing some strange behavior on my Commodore 1541 and FSD-1 disk drives. Both drives seemingly work fine when attached to the C64 by themselves, but if I set the FSD-1 to be device 9,10 or 11 - and also attach the 1541 (as device 8) I get the following problem: If I turn on both drives, and then turn on the C64 the reset/initialize signal is sent to both devices and they momentarily light up…
None of the 16-bit registry code was carried over to Windows 95. Windows 95 extended the registry into kernel mode, added support for values and non-string data types, increased the maximum registry size (though if some people are to be believed, not by enough), and added a bunch of other hives, like added the HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, and the HKEY_DYN_DATA What was the registry like…
Around 1988-1990 I worked for a company that was using an old RSX-11M system to host an ERP (Enterprise Resource Planning) application. The application used a third-party database product of which I am trying to recall the name. This was a hierarchical/navigational type of database (not relational). The system had been in-use for some years prior to 1988, was becoming obsolete at that point,…
In the mid-1970s,there was a big time sharing CDC service center in Waltham, MA. I'm curious what it cost to run computer jobs there. (My long winded story follows) In 1976, I had a summer job of "shuffling" decks of cards to pass to a CDC 6600 machine. My employer had this great big engineering simulation that took 30 minutes to run. My job was to, Prepare a deck of cards to pass to the machine,…
I am looking for a game from the end of 80's/early 90's game on Atari ST. Where two wizards, one purple, one red have to turn the color of a checkerboard tiles to its own color using spells. The main screen in game as the aspect shown on the linked image. It seems that the game is an advanced version of Hex on Amiga/Atari ST (1985). The sorcerers is clearly inspired from the bearing lantern…
I'd like to run an old-school BBS that can be dialed into over a real phone line. Unfortunately, I don't currently have the necessary hardware to do so. I had the idea of purchasing a VPS and then using an SIP softphone and some BBS software to accomplish the same task. The only problem is that I can't find anything that emulates a modem. I'm aware of a program called minimodem, but that seems to…
I hope this is appropriate to ask here, if it's not, please let me know and I'll get it deleted. So, for YEARS , I have been searching high and low for old copies of a Tandy 1000 and Tandy portable specific magazine called PCM . It was published by Falsoft and has been out of print for a long time. I used to read these magazines when I was a teenager and learned quite a bit from them. Now in my…
I installed Windows NT 3.1 on a Compaq ProSignia 3080 system, because of several reasons: I know that this machine was running Windows NT 3.1 when it was in productive use. And I think this machine was one of the machines Microsoft explicitly targeted with Windows NT. For improved performance, I maxed out the RAM at 128MB and swapped the socketed Intel 486DX-33 by an AMD enhanced 486DX4-SV8B…
I have a game that I can play in a Windows 3.1 emulator. Now I want to have a look "behind the scenes" of the game EXE file. I hope to find game graphics (sprites) there. But how can I extract it? Every unpacker that I tried says "Not a valid PE file".
I'm wondering how to write a program in Z80 assembler that discovers the value stored in the SP register. From what I've seen, the only instructions that touch the SP register are: LD SP, HL/IX/IY EX (SP), HL/IX/IY PUSH / POP However, none of them seem to load the address stored in the SP register anywhere. Is there a way to do it?
In the early seventies, companies like HP and Wang sold 'programmable desktop calculators' that were really personal computers in the time before what is usually thought of as the dawn of personal computers. At the same time, there was a demand for small computers to control lab and factory equipment, and this demand would tend to occur in the same sort of places as would be buying desktop…
ed was the standard Unix editor, and is present on all POSIX certified systems (though it's not installed by default in Debian, FWIW). It's a line editor (meaning, you can't see all the text at a time. You query line numbers and it spits it back, but it came before vi[1], where you can use hjkl to navigate up and down the screen). How was it used? I find it hard to believe that people memorized…
I'd like to do a presentation using my Apple //e as the video generator. Is there any good "slideshow" or presentation software for the Apple //e other than writing a BASIC program to draw on the HGR screen. Preferably I'd like to author the images and/or text on my PC, and the ADTPro a disk to the Apple //e to show off the slideshow. Understanding the limitations of disk size, I expect the…