All Questions

The earliest business data processing systems were based on batch processing of punchcards. Prepare cards off-line, feed a batch of them through the computer. (Why does one so often hear of payroll, ...

I am looking for impressions, memoirs, articles, guidelines - everything that is possible about the unusual direction of software migration. I am interested in non-Unix related code, and preferably ...

According to https://en.wikipedia.org/wiki/Data_General_Nova The Nova 1200 executed core memory access instructions (LDA and STA) in 2.55 microseconds (μs). Use of read-only memory saved 0.4 μs. ...

The SABRE airline reservation system went online in 1964, astonishing the world by being among other things the first large-scale interactive computing system. Once the IBM 3270 video terminals were ...

According to https://en.wikipedia.org/wiki/VT05 the VT05 presented the user with an upper-case only ASCII character display of 20 rows by 72 columns. At first glance this seems a reasonably natural ...

According to https://en.wikipedia.org/wiki/VT52 Like other early DEC terminals, the VT50 series were equipped with both an RS-232 port as well as a 20mA current loop, an older serial standard used ...

Nowadays, in corporate offices where there are typically several office printers per floor, sending a file to a printer does not result in any additional pages identifying the print job, at least by ...

Yesterday I was looking for a way to implement a delay loop on the C64. I came across this page: https://www.c64-wiki.com/wiki/TIME At the bottom of the page there is a code fragment that waits for a ...

I currently enjoy using a Windows 98 PC I built using parts I got either for free or very cheap. One of those parts is a sligthtly modern case - the cheapest one I could find that has a 5.25" and ...

The VIC-II and SID chips in the C64/128 are prone to over-heating and are rather expensive to replace nowadays. Some other ICs in these machines may have the same issue. An unmodified machine includes ...

I have been using the following code to get comm port addresses from BIOS in QuickBasic 4.5: PRINT "Hex addresses for ports 0 to 3 from BIOS." DEF SEG = 0 FOR x = 0 TO 3 z = &H400 + ...

The device I'm using (a SYM-1, probably c. 1979) has a stack of L2114-UCE 1024x4 static RAM chips ("2114 static, TTL in/out 1024x4 N-MOS RAM", the -UCE means "450ns access time, 315mW ...

I have a SYM-1 with the following memory configuration: How much memory is that? Those all appear to be L2114UCE chips, which are described as "Static 1024x4 NMOS RAM", but I'm not sure how ...

My desktop computer is no longer manufactured and no longer supported since more than 18 years ago. It was a very expensive top of the line business computer back in the day. I like it and wish to ...

Using an USB external floppy drive, I've been able to use my Mac to back up files from a big box of 3.5 inch floppies (800K, HD 1.4MB). But I cannot even read my DS 1MB floppies using either the ...

Running SUPERMON on a Synertek SYM-1, the R (REG) command cycles through a number of registers. Most are self explanatory: p is the program counter (pc) s is the stack pointer a, x, and y are obvious ...

Some early models of Intel 80386 processors had a bug with 32-bit integer multiplication. Those which were found to have the bug were marked "16-bit S/W ONLY" (not sure what S/W is supposed ...

The curses library is a terminal control library for Unix-like systems used in text based user interface applications. It has been used in many games in the past. It was developed by Ken Arnold and ...

Is there a historical reason? Since it is rewritable it isn't read only by definition, so why call it so?

I tried this code in my assembler, set to 16 bit mode: bits 16 rep mov ds, ax Surprisingly, no error was thrown. Is this even valid? Wasn't rep only supposed to work with string instructions? Is it ...

Not sure if retro is proper place... I have two old notebooks with x86 processors in the 100s range of MHz. While nostalgics might appreciate them, I'm wondering if there is any proper point in ...

While reading about the SuperPET I just recalled another PET modification. My uni had an 11/780 that I learned FORTRAN on. It used modified PETs as input terminals. This took the form of a modified ...

The TX-0 has a class of instructions very similar to the PDP-style microprogrammed, operation instructions. Fill the opcode field with all ones, and then select which microoperations you want to ...

Having disabled BASIC and Kernal routines I set up an IRQ to run the following code when the raster line reaches 200: .irq1 inc 53280 // change border colour // lda #$ff // clear the ...

Platform(s): PC (Used to play on Windows 95/98) Genre: 2D Platformer, Puzzler, Indie, Overcome some square obstacles, Exit to door or portal next level (100 levels approx if not a bit less or more) ...

I have a console, but not the main computer it's designed to connect to. My goal is to interface this with a (Linux) PC, and hopefully more than just the keyboard. I have never tried something like ...

I'd like to upgrade my Macintosh II to FDHD, I have a SWIM chip (to replace the WIM chip), but don't know how to burn the ROMS. The upgrade process I'm trying to do is described in the book: "...

A couple of days ago, I was given some old tapes with programs written on them. However, I am having some trouble with them. I do not know what computer they were programed for. After recognising the ...

I'm interested in IP networking capabilities of the Commodore 64. I learned there is a tool called WarpCopy64 that can be used to run a simple file server on the Commodore. The server can be accessed ...

Windows Management Instrumentation (WMI) was made available as a separate download for Windows NT 4.0 SP4 and above. I know that WMI installs and works great on Intel IA32 (x86) flavors of NT4, ...

Memory corruption bugs have always been a common problem in large C programs and projects. It was a problem in 4.3BSD back then, and it's still a problem today. No matter how carefully the program is ...

The March 1988 issue of RUN contains the following tip from a reader on page 20: Attention: C-128/1902A Owners! If you use a Commodore 1902A video monitor with your C-128, here's a way to get a ...

In the non-OOP programming languages that I know of, you can't make a variable private (i.e. there is no private keyword), but there are some tricks that you can use to effectively make a variable ...

I was wondering if it is still possible to access any online BBS using dial up and an 80's era computer. I'm aware that some dial up internet providers still exist (eg Nippy Internet in the UK), but ...

Sorry if this is too recent, but back when I was first getting into programming in ~2002-2004, there was some Flash/SWF-to-EXE tool that provided ActionScript bindings to Windows desktop APIs. Does ...

I delved a bit into the origins of (commercial) timesharing and it seems there have been very interesting computing hardware and software (architectures) which have become relatively unknown but may ...

I'd like to JSR or JMP (preferably JMP as it's 3 cycles cheaper) to an address stored somewhere else in memory, the address of which is itself indexed. I came up with the following self-modifying code ...

I have a Thinkpad T41 on which I installed Windows 98 SE. I installed an old DOS game, and was wondering if I could get a USB mouse to work with it ? (the PC doesn't have a PS/2 port) At the moment, ...

The C64 and the C128 have a memory for storing the color values of a character. The size of this memory is 1k x 4bit (2k x 4bit for the C128 which can do a double buffering), thus reading the value at ...

In this Stack Overflow question the original code made the mistake of using the function name as a variable, and assigned the return value to it. A commenter mentioned that he once used a language ...

Why did IBM decide to use 8 bits for EBCDIC? 7 bits per character seems reasonable, since 2^7 = 128 symbols which is enough for all English letters and special symbols.

I'm having trouble accessing HTTPS websites using Netscape Communicator 4.8. This is the error message I get: Is there a way I can configure some sort of proxy that will allow me to access HTTPS ...

Modern out of order CPUs can do all sorts of things in parallel, having not only multiple functional units, but a lot of logic to check at runtime exactly which instructions really depend on others, ...

Dynamic RAM is denser than static RAM, but needs to be refreshed every few milliseconds to avoid losing data. How many milliseconds, exactly? If the answer has changed over time, then I'm interested ...

Arcade strider game show level name use different language follow Strider Hiryu (飛竜)'s adventure. But I not recognize languages for level 3 and level 5. Can see titles in this video, Arcade Longplay [...

Does there exist either an embedded task manager, or a third party task manager for for Mac OS 8/9? So I can: View currently running tasks Kill processes View system load

I have a function that should be callable with the following syntax: void __fastcall__ initSIDplayer1(uint8_t a); The __fastcall__ modifier here means that the argument is passed in the Accu instead ...

I recently sold a defective Amiga 1000 on Ebay for over $300. I'm going to list my old Amiga 1200 and expect to get over $1000 for it since its working and "souped up". This made me wonder: ...

Would somebody care to explain how "Super Mario Bros." was released in 1985. But the DASM Assembler came out in 1987? The 6502 Assembly language was introduced in 1975. How would you compile/...

I've been looking at a bunch of different 6502 assemblers recently (dasm, ca65, xa, kickass), and many of them have support for multiple code segments. Some of these assemblers can generate ...