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Forum Index : Microcontroller and PC projects : Benchmarking Original 80's Kit
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Nimue Guru  Joined: 06/08/2020 Location: United KingdomPosts: 420 |
Evening all So I bought an apparently "dead" Acorn Electron from Ebay. I was going to gut it and use the body as a new case for CMM2 When it arrived, a quick look found only a few snags: (1) The power transformer cord was frayed (desoldered and fixed it) (2) The power socket in the electron had become desoldered (re soldered and fixed) (3) On power on, the "L" key was sticky (disassembled it and cleaned every key with contact cleaner). The result is a fully functional Electron that I dont want to part with. So, I did what I do and wrote the following benchmark: Timer = 0 For x = 1 To 10 For y = 1 To 10 For z = 1 To 10 c = (Sin(z+y)+Cos(y+z)+Tan(x+y)) d = c Mod z e = Int(c) Next z Next y Next x Print Timer On my i7 / Windows 10 - this takes 0ms On the CMM2 this takes 25ms On the Electron this takes: 144820 (145 seconds) So, I was wondering -- does anyone in the 'Shed have functional '80s / 90's kit (C64 for example) and would be willing to run up the above code and share the outcomes? I feel like poking round eBay to get my hands on some 80's nostalgia -- it seems that the focus is always on games and "coding" related to games. But "BASIC" back in the day was also used for serious number crunching and it would be really interesting to see how old kit stacks up. I also now realise just how much I love the Electron keyboard and the coding experience on real, full travel "clicky" keys. Nim Entropy is not what it used to be |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
This series of benchmarks happened a while ago, to give you some idea:  |
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CircuitGizmos Guru Joined: 08/09/2011 Location: United StatesPosts: 1427 |
This was the first thread: http://www.thebackshed.com/forum/ViewTopic.php?TID=4685&P=1 Edited 2021-03-26 09:20 by CircuitGizmos Micromites and Maximites! - Beginning Maximite |
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| Nimue Guru Joined: 06/08/2020 Location: United KingdomPosts: 420 |
Thank you both -- will follow up those benchmarks. N Entropy is not what it used to be |
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CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2170 |
that is true. in the middle 80s I worked for a company that made all sorts. at the time, my crowning glory was gutting Amstrad CPC6128s and embedding them in refurbished radar consoles for Plessey (the resultant beast being a plug in for the WF33 "Alladdin"). At the time it was revolutionary because the data gathered from a met balloon was mostly gathered by hand, the PILOT or TEMP (standard "messages" that captured the important bits of an ascent and got TELEXed to the met office in UK) were then compiled by hand on pre-printed photo-copied sheets. The software I wrote would do all that tedious stuff and produce a lovely printed message at anytime in the flight (so long as the balloon was above 3000m) as well as archive them on disk. You had to spend a kings ransom on Vaisala or VIZ kit to get that in those days. Some of the maths was pretty hair-raising to me at that time - my first taste of Chebyshev polynomials to convert the sonde frequencies to actual pressure, temp & humidity for the TEMP message. All done in Basic - we had some machine code in there in the form or an RSX pack that just speeded-up things like stashing the flight data in the extra 64K of RAM and switching the screens between RHI (Range/Height Indicator) and PPI (Plan Position Indicator) - even a graphic display of the ascent progress was rare - all done easily on a humble home 8-bit. We converted to QB later as PC compats were taken more seriously than a "toy" computer *sigh* bit snobbery is nothing new. I still got that version of the software somewhere. Next time I am visiting Ken's widow, I will see if I can snag some pix to scan in and post on my website as a more permanent record. Oh, btw. F4 is 218 Edited 2021-03-26 18:06 by CaptainBoing |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 5089 |
Many companies did: Rare VIC20 One of my friends started a company in programmable disco lighting with similar machines. This was a golden age... PicomiteVGA PETSCII ROBOTS |
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| Nimue Guru Joined: 06/08/2020 Location: United KingdomPosts: 420 |
The last thing I need is 8bitGuy distractions -- I'll not get anything done now.  N Entropy is not what it used to be |
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| Nimue Guru Joined: 06/08/2020 Location: United KingdomPosts: 420 |
Really interesting and a good insight into what was possible in less than 128Kb and sub 10MHz. Thanks for sharing and testing. N Entropy is not what it used to be |
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RetroJoe Senior Member  Joined: 06/08/2020 Location: CanadaPosts: 290 |
Nimue, you forgot the decimal point - it should be "sub 1.0 MHz". Almost all of the early 8-bit machines chose a CPU clock speed that could be used to derive composite video signals. The C64's clock speed was region-dependent: 1.023 MHz for the NTSC version, 0.985 MHz for the PAL version. So, if you lived in Europe, you were penalized for using the PAL system by a slightly slower Commodore! All well below 10MHz, though. Z-80 machines were typically clocked around 4MHz, but they needed a bunch more clock cycles to complete most of their instructions, so the effective performance was about the same as the single-clock cycle architecture of 1 MHz-ish 6502 machine. Even the original 68000 Macintosh was only clocked at 8MHz and had 128K of RAM - remarkable, really, when you compare it to the giga-monsters of today. Enjoy Every Sandwich / Joe P. |
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| CaptainBoing Guru Joined: 07/09/2016 Location: United KingdomPosts: 2170 |
yes and your point about video signals meant for PAL, Z80 based machines usually ended up at 3.58MHz.  The Z80 was a super-set of the 8080 and copied many of it's features to ensure compatibility with bus and code timings. The least time you could expect an instruction to complete was 4 clock cycles, which meant very often it struggled to hit 1 MIP and compete with 6502 based machines. 6502 was a very different approach (what with zero page and all) and at 2MHz ran like a stabbed rat. Z80 made up for it with super-simple bus and clock plus some nice trinkets for dynamic RAM refresh (although the R register was stupidly only 7 bits *rolls eyes*) The Z80 was further hampered by a 4bit ALU (oh yes, it was! https://electronics.stackexchange.com/questions/196105/how-can-z80-uses-a-4-bit-alu-and-return-results-in-a-single-clock-cycle) This disappointing lack of speed for the Z80 in some areas, meant that a lot of its very nice advances over the 8080 e.g. indexing instructions, went unused because you could achieve the same with more traditional methods and often quicker. Very much a case of concepts being mired by disappointing design execution. Was still a lovely CPU to write for though. Edited 2021-03-26 20:57 by CaptainBoing |
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thwill Guru Joined: 16/09/2019 Location: United KingdomPosts: 4311 |
Hi Nimue, Assuming you are still interested in the answer to your original question, my BBC Master 128 managed it in 32 seconds:  This goes down to 30 seconds if you use the "resident integer" variables, i.e. stick % after all the single variable integers. I'm a little surprised it is over 4x faster than your Electron. I'm not an expert but it's a 65C12 processor (a souped up 6502) running at 2 MHz. With old Beebs the Rifa capacitors in the power supplys like to go pop, let out their magic smoke and spray goo over the motherboard, and with the Master the CMOS battery likes to spill over everything too. The Electron doesn't have the battery, but it may have the same problem with the capacitors. The "Acorn Computer and BBC Micro Enthusiasts" group on Facebook can advise you on how to keep it alive and give it some TLC. Mark Haysman @RetroClinic on that group is the main guru and the man to see for any bits. Best wishes, Tom MMBasic for Linux, Game*Mite, CMM2 Welcome Tape, Creaky old text adventures |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
Keyboard: I probably wouldn't go for this particular model again because it makes you jump through too many hoops but the Motospeed CK62 mechanical keyboard Is a joy to type on and has survived not-so-gentle treatment in my backpack. I prefer using it with the USB-C cable because the Bluetooth tends to irritatingly drop characters. |
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| RetroJoe Senior Member Joined: 06/08/2020 Location: CanadaPosts: 290 |
I would run the benchmark on my Apple IIe, but it doesn't have a real-time clock chip, nor a "soft clock" timer routine in ROM, hence no TIME or NOW function in AppleSoft BASIC. @CaptainBoing, agreed - I enjoyed writing Z80 code more than 6502 code. The 6502 was a real barebones affair, whereas the Z80 had upholstered seats. I also worked a bit with the Motorola 6809, which I would argue was the pinnacle of the 8-bit era - it was the 6800 "done right", but arrived too late and was too expensive to make an impact, and was soon eclipsed by 16-bit and 32-bit chips. I believe the Tandy Color Computer was the only moderately successful home machine to use it, but it was used by Williams extensively in their signature arcade games e.g. Defender, Joust and Robotron. Most of my 6502 work was on the Apple II, which compounded the barebones CPU with Steve Wozniak's penny-pinching design philosophy - it has zero dedicated audio or video hardware, and the DRAM refresh is accomplished through clever video timing and memory access tricks. A real bear to program games on, and a real testament to the pioneers who produced such high quality ones. "Prince of Persia" was particularly jaw-dropping when it came out for its fluid and lifelike animations. These were achieved by manual rotoscoping - the author videotaped himself running, leaping, climbing et al, then laboriously mapped each video frame, pixel by pixel, to pseudo-sprites. Seems like a technique we could recreate today on the CMM2 :) Enjoy Every Sandwich / Joe P. |
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| Nimue Guru Joined: 06/08/2020 Location: United KingdomPosts: 420 |
Yes, still interested in the speed test -- thank you. I have had the Elk apart -the power supply (transformer) is supplying 19-20V AC to the PSU. The PSU is spitting out +/- 5V DC and passes through the 19-20V AC. Will follow up yuor suggestions. N Entropy is not what it used to be |
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| Paul_L Guru Joined: 03/03/2016 Location: United StatesPosts: 769 |
Keyboard ...... There's only one keyboard I can bear to type on .... Unicomp .... pckeyboard.com. This is the original IBM keyboard! When IBM spun off the PC subsidiary to Lenovo they sold the patents, production equipment and building for the buckling spring capacitive key switch keyboard to the employees who worked in the keyboard plant in Lexington, Kentucky. They are still there on Henry Clay Boulevard! The keyboard still weighs 7 pounds. It doesn't slide around easily while you're pounding on it. It still sounds like a 1947 Hudson going over a railroad crossing. It still provides real tactile feedback to your fingers. It still is eminently useful as a substitute for a baseball bat should a mugger attempt to interrupt your typing! They rebuild old keyboards for about half the price of a new one, so once you buy one you'll have it as long as they stay in business. Paul in NY |
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| RetroJoe Senior Member Joined: 06/08/2020 Location: CanadaPosts: 290 |
I too have a couple of IBM "aircraft carriers", and they are truly indestructible. I think we need to start a "Show Us Your Vintage Keyboard" thread :) Enjoy Every Sandwich / Joe P. |
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| Volhout Guru Joined: 05/03/2018 Location: NetherlandsPosts: 5089 |
The electron was less than half the speed of the bbc. This was mainly because it uses only 4 bit wide memory. PicomiteVGA PETSCII ROBOTS |
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| Tinine Guru Joined: 30/03/2016 Location: United KingdomPosts: 1646 |
And another for the stories, I love reading this stuff.  |
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