Coincidentally, this link to photos of a Wang 2200 came through a facebook group today. Apparently he recently acquired one.
Will https://www.icloud.com/sharedalbum/?fbclid=IwY2xjawKIevhleHRuA2FlbQIxMQBicmlkETFtb3YxUHpBRnZ5QnlJUGFuAR5jcMRIH9jACdejVSeRcDn7rOINwo8s0v0_MaGzHOkKvOh_4082rb7ZwqgRnw_aem_kRxA2kc8dT0rptH0GpU6_Q#B2SGrhkPxGqMPcS > On 05/07/2025 5:54 AM EDT Martin Bishop via cctalk <cctalk@classiccmp.org> > wrote: > > > Steve > > Thank you for the link to Shrriff (below) - interesting and with valuable > references, including from the commentariat > > Folks > > Two microprogramming URLs worth following up - both pdfs > https://ed-thelen.org/comp-hist/MicroprogrammingABriefHistoryOf.pdf 2012 > commentary on microprogramming > https://baltazarstudios.com/webshare/A-Z80/Library/Demystifying%2520Microprocessor%2520Design%2520-%2520M.%2520Shima.pdf > Z8000 design retrospective > > Enjoy > > Martin > > -----Original Message----- > From: Steve Lewis via cctalk [mailto:cctalk@classiccmp.org] > Sent: 07 May 2025 05:50 > To: General Discussion: On-Topic and Off-Topic Posts <cctalk@classiccmp.org> > Cc: Steve Lewis <lewiss...@gmail.com> > Subject: [cctalk] Re: Wang TTL BASIC > > For reference, Shirriff describes aspects of the 8086 microcode here How the > 8086 processor's microcode engine works > <https://www.righto.com/2022/11/how-8086-processors-microcode-engine.html> > https://www.righto.com/2022/11/how-8086-processors-microcode-engine.html > > Including a reference to 1951 Wilkes concept. > > As the S/360 used microcode, I'm suspect if PALM used some form of microcode > (which was developed at or near Boca Raton c.1971, but not much is known > about it -- we have its instruction set documented as early at 1972, and the > "M" is PALM is said to be Microcode). Just unclear what they really had > going on in those SLT modules. > > But back on the original Wang question: I still can't find high resolution > images of it's CPU board. According to 1991 discussion here on the 2200B, > there is also mention of the system not really having an instruction set, > BASIC was all it could do since it was "hard wired." > https://groups.google.com/g/alt.folklore.computers/c/lb0DzzDja-Y > I would think by 1991 they knew what a ROM was and would have called it as > such, so I'm still curious if we have right on how that system worked. > > People may have had that impression about the IBM 5100, but we've showed it > has a DSP (kind of diagnostic mode) where you code in PALM machine code (or > even load "binary blobs" of previously stored PALM code onto tape [ video on > it here, towards the end I load an IBM 5100 ported version of Corti's > original one he did for the 5110 https://www.youtube.com/watch?v=e2GYWyZyfpE > ]), and the earliest PALM instruction docs we have is from 1972. That doc > doesn't describe how many cycles each instruction takes, but I think in the > IBM 5100 SLM docs it does imply they have a variable number of cycles. > > > > > > > On Mon, May 5, 2025 at 4:18 PM Brian L. Stuart via cctalk < > cctalk@classiccmp.org> wrote: > > > On Mon, May 05, 2025 at 04:09:29PM +0100, David Wade via cctalk wrote: > > > I think "Microprogramming" as a technique has been around as long as > > > we > > have > > > had computers. Couldn't the setting up ENIAC to behave like a stored > > program > > > computer in 1948 be described as "Microprogramming"? > > > > That's an interesting question, but I'd say yes. I base that on the > > idea that microprogramming is essentially programming one universal > > machine to emulate another universal machine with the purpose of using > > the programming model of the second machine as one that is more > > convenient than that of the first. Of course, it doesn't look at all > > like the microprogramming we're used to, but I'd say it still applies. > > > > > > The Zuse Z1 from 1936(!) was microcoded, too. It implemented for > > example > > > > floating-point arithmetic and conversion instructions > > > > (binary<-->decimal). > > > > > > > > Christian > > > > I'd add that we can go back even farther. Babbage included a > > mechanism on the analytical engine for the more complex operations > > that was effectively microcode. I was implemented with a cylinder > > (referred to as a barrel) that you could screw blocks into. A set of > > levers were pressed against a line of block positions along the length > > of the cylinder and the presence or absence of a block would determine > > whether the connected mechanism is engaged. Then the cylinder is > > turned one step and the process repeated. The whole thing ends up > > being a lot like typical horizontal microcode. > > > > BLS > > > > You just can't beat the person who never gives up. Babe Ruth
