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The Atari 2600, along with others like the Odyssey 2 or Intellivision, were among the first programmable home game consoles. They existed alongside personal computers like the Apple II and Commodore PET. But what, if any, special hardware was available to developers at the time to test and debug their games before sending them into production?

My naïve assumption is that there was virtually nothing. My guess is that a game would be designed, probably a good deal on paper, and entered into a computer like the Apple II to perform any final assembly into machine code.

To test it the file would then be burned onto an EEPROM chip using an attached writer and the chip would get transferred into an open cartridge with a ZIF slot to be played on a retail console. Any bugs would have to be resolved using pure thought and deduction (although this was still in an era where debugging on paper was both practical and practiced).

But that's only my assumption. Were there any known hardware development kits, either official or hacked together by developers? Ones that might've allowed breakpoints, like a modified Atari using a full 6502 with its interrupt lines and additional address space for a system monitor ROM.

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    forums.atariage.com/topic/… has some speculation. I'd second using a PDP-11 as the software development environment as one good option.
    – Jon Custer
    Apr 8 at 17:19
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    In the "Once Upon Atari" video series, there are some references to the developers working on consoles over a network, so a PDP-11 or similar is a definite possibility. Apr 8 at 18:21
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    The photo on the front cover of HSW's new book shows some interesting hardware. And here's another interesting photo. Apr 8 at 18:42
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    Exploring Jon Custer's link turns up this photo content.invisioncic.com/r322239/monthly_10_2013/… and I notice that it too has the same black backplane style case as Noel Whitemore's photos. You can see it has several modules with ribbon cables and a prominent one with the Atari logo on it. Terminal wise the 'last day' photo looks like a VT100 while the others have what looks like the TeleVideo 925. The first two photos also have another system with a very small integrated CRT and hex keyboard but I don't know what it is.
    – David
    Apr 8 at 19:13
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    EEPROMs (as in your question) weren't really present in 1977 (They were just invented the very same year). What was available was battery-backed static RAM as an EPROM simulator or "real" EPROMs.
    – tofro
    Apr 9 at 13:15

2 Answers 2

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Since none of those early systems featured any custom designed CPU, generic development systems / In Circuit Emulators can provide all luxury needed.

GI, first of those offered, beside cross-assembler support, their GIC1600 development system as shown on p.88 ff of the May 1975 catalogue.

MOS did the same. Already before the first 65xx chips were available

  • cross-assembler on time sharing systems was made available.
  • Soon after (1977) the MDT-650 (Microcomputer Development Terminal for 650x) was available (*1)
  • Followed by the KIM-1
  • Later that year a set of brown boxes were produced (*2), eventually the most professional of all MOS/Commodore provided 650x development tools (*3)
  • Followed in 1978 by the MDS 650 (Microcomputer Development System for 650x) which was a modified PET 2001 32N with a 2040 floppy drive.

For the Z80 Intel development systems could be used at first, followed by Zilogs Blue and White MCZ boxes, commonly known as Zilog Z80 Development System, according to their front plate.

Most of those hardware based system had, one way or another, ICE like capabilities supporting partial or full cycle exact execution trace and complex traps/breakpoints, like the Real-Time Debug Module for Zilog's MCZ:

Real-Time Debug Module description

(Taken from the April(?) 1976 Product Specification brochure)

Often full ICE probes were available to trace and inspect the target system. For the MCZ this would have been the In-Circuit Emulation Board:

In-Circuit Emulation Board description

Systems from other manufacturers (GI, Intel, MOS, Motorola) could be fitted with similar boards.


Of course all of those were professional systems usually way past 5k USD. Rather out of reach for hobbyists or real garage startups.

Then again, by 1978 a multitude of (native and non native) systems could be used for either CPU, as all needed was an assembler (could be written over a weekend) and a PROM burner to get started. When ROM production was about, adding a paper tape punch would be handy.


Also, paper based development was always the base stage before touching any IDE, no matter how capable. It was simply faster to look at paper and think a bit than running a compile/execute cycle.


*1 - Used at Commodore to develop the PET

*2 - I got a set in storage, but really no idea what it was called.

*3 - Rockwell might have had some real nice development/ICE systems as well, although I do not have any documentation for them.

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While I don't think anyone outside Arcadia/Starpath had the software necessary to exploit this, anyone with an Apple II, an Atari 2600, and an Arcadia/Starpath Supercharger would be able to develop an Atari 2600 game with a development environment that was probably no worse than what early Atari programmers would have had (they would have been using a time-share minicomputer that was in some ways more powerful than the Apple II, but the Apple had full-screen editing, and could probably feed code to a SuperCharger/2600 system that wouldn't need to be shared with anyone else, with no EPROMs required).

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  • Beside that the Supercharger wouldn't provide any of the features the question asks for, it also only became available in 1982, right in time for the video crash of 1983 (and when third gen became a thing with the Famicom). Also the reason why it was already discontinued in 1984 - no market anymore.
    – Raffzahn
    Apr 9 at 2:23
  • @Raffzahn: The combination of Apple II, Atari 2600, and SuperCharger was used back in the day to develop most of the games in the Arcadia/Starpath catalog (Rabbit Transit is, if I recall, a 4K game that doesn't need the SuperCharger's RAM and could have been developed via more conventional means and then just marketed by Starpath/Arcadia). While it didn't become available until fairly late in the 2600's life cycle, the hardware was available at retail back in the day.
    – supercat
    Apr 9 at 3:02
  • No need to argue about something that hasn't been said. Question asks about environments available and providing more than the bare minimum.
    – Raffzahn
    Apr 9 at 11:09
  • @Raffzahn: The ability to load a game without having to swap EPROMs would have been a substantial upgrade compared iwth the "bare minimum" approach of using an EPROM burner and socketed cartridge.
    – supercat
    Apr 9 at 14:46

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