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Faicuai

Member Since 5 Apr 2011
OFFLINE Last Active Apr 10 2019 7:49 PM

Topics I've Started

A800 vs IBM/PC 5150: Because now is the time...

Thu Dec 20, 2018 12:12 AM

I will start by saying that have a soft-spot for the legendary IBM-PC 5150... a true "maverick" product, born out of true mavericks inside what was otherwise a rigid and gelid corporate culture... Conceived and designed right here, in Boca Raton, Florida, from where the Personal Computer revolution was catapulted to a multi-billion industry stardom!

 

Yes, the PC 5150 carries a more powerful Intel 8088 CPU running at 4.77 Mhz, filled with 16bit registers and 1 Mbyte of addressable RAM, has a more capable, "open" architecture, also costing a whole lot more than the Atari series... yet its CPU handles 8-bits at a time, on its data-bus !

 

I always perceived the 5150 as being significantly faster, especially after seeing those dreary benchmarks of the time (almost all in Basic), in which most of the time, our A8s got deeply buried. But with the flurry of Basic interpreters and compilers recently optimized and/or developed for A8-series, maybe it is now the time to revisit history.

 

For the IBM side of the tests, we will use:

  • PCjs (https://www.pcjs.org...achine/5150/mda) simulation
  • Monochrome Display Adapter (MDA), 256 Kbytes of RAM.
  • PC DOS 3.1 and its 16+ Kbytes PC-Basic package (which only runs with on-board 32K disk or cassette-Basic !!!)

As for the Atari, tests will be run on :

  • Real 800 running in both OS-b and XL modes (with Incognito) will be used.
  • The basic of choice will be Altirra Basic 1.55 (8k interpreter-in-rom package that 1:1 replaces Atari revC),
  • Altirra OS (higher-precision) FPP in XL/XE mode
  • Newell FPP for OS/B
  • SDX as facilities environment. Any other DOS is also possible.

 

Test #1: AHL's bench:

 

Atari (34.2 secs):

Attached File  IMG_3423.JPG   686.19KB   10 downloads

 

IBM (23.56 sec):

Attached File  IMG_3438.JPG   795.43KB   10 downloads

 

NOTES:

  • A800 results are about 100x (hundred) times more precise than IBM's, thanks to Altirra's FPP package.
  • On OS/B Newell, Atari timing is 24.36 secs. with precision similar to IBM.
  • On high-performance FPP package for XL/XE OS, A800 execution time drops to 19.95secs, with precision similar to IBM.
  • All tests with Antic OFF

 

 

Test #2: integer-looped / cumulative & carry-over FPP basic operations:

 

 

Atari: (72.53 sec, Error=0)

Attached File  IMG_3437.JPG   648.83KB   10 downloads

 

IBM: (74.6 sec, Error=0)

 

NOTES:

  • Microsoft Basic II for A800 completes these tests in 74.5 secs.
  • On OS/B Newell, Atari timing is 78.4. secs, with lower precision.
  • On high-performance FPP package for XL/XE OS, A800 execution time drops to 50.90secs, with lower precision.
  • All tests with Antic OFF

 

 

Test #3: Prime Number Generator (size = 1000)

 

Atari: (7.72 secs)

Attached File  IMG_3430.JPG   801.94KB   10 downloads

 

IBM: (13.00 secs)

Attached File  IMG_3429.JPG   856.77KB   10 downloads

Attached File  IMG_3426.JPG   664.81KB   9 downloads

 

NOTES:

  • The executed Basic code (IBM and Atari) for this test are essentially IDENTICAL.
  • The A800 was switched to 80-cols. mode in SDX, and Antic was left ON during the execution of the test.
  • The IBM code was optimized for handling Integer-variables directly (A800 basic does not support such direct definitions).
  • When deliberately suppressing screen-output (but ANTIC=ON), A800 runs in 4.x secs. and IBM in 9.x secs. 
  • It is clear that A800 is handling HIGHER screen-output overhead than IBM, even with Antic=ON.

 

Well, there you have some food for thought... With just a more efficient / intelligent Basic interpreter and a more optimized FPP package, the A800 seems to be showing fairly competitive performance with respect an IBM 5150 on some past and modern Basic tests (the testing venue of choice back in the day).

 

Forget about the Apple II and (much less) the C64. Those will never match these results.


A800-i (Incognito): Bringing back the RIGHT-Cart port...

Sat Dec 1, 2018 12:30 PM

...Let's face it: two cart ports is better than one, four joystick ports are better than two, five (5) motherboard slots are better than NONE... and with Incognito, yes, almost everything is better on the A800 than anything out-there...

 

...BUT, as you may contemplate all this A800 goodness, there's unfortunately a catch... In fact, there is a price to pay when upgrading to Incognito, as you may later understand.... because, once everything is said and done, your RIGHT-Cart port (CartB) will become unusable in all XL/XE modes!... sort of an engine that somehow manages to work with one cylinder while the other is pretty much dead...

 

As you may (rightfully) imagine, contemplating that nice, internal dual-port cart-bay, with the right-slot being pretty much an ornament, can place a big toll on any of us! … :) Well, no more !

 

Introducing OS-XL load with "rC" (right-Cart) extensions, so you can bring back to life that dormant right-port and boot your favorite right-carts reliably, and in a plug-and-play basis!

 

Attached File  A800-rc_OS_Extensions-1.jpg   202.72KB   22 downloads

Attached File  A800-rc_OS_Extensions-2.jpg   192.08KB   22 downloads

 

A few highlights worth mentioning:

  1. Based off latest, most robust (and space constrained) XEGS (rev4) 1987 OS load.
  2. ALL native OS improvements and functionality remain INTACT / untouched! (e.g. XEGS keyboard, Int'l character set, etc.)
  3. Includes rC extensions with re-implemented CartAB boot / initialization / start manager. Deeper analysis of OS-B and XL/XE boot logic was involved.
  4. Re-coded Cart AB signature detection, validation and initialization, with CartB (RIGHT) priority, as originally intended in OSb.
  5. It is now much harder to crash the boot-logic by plugging phantom / invalid 8k carts on either port. Cart-initialization and start during power-up will not crash as easily as in native OSb, and you will still have access to media boot, for further analysis.
  6. NON-contiguous $8000-$BFFF memory space is supported, exactly as it is on OSb: you can now plug your right-cart and boot A800i with OPTION key-held, OS will size memory to $8000, and RIGHT-cart will be booted... while $A000-$BFFF will remain as USABLE RAM (!)
  7. As an extra bonus, the following features are included on this OS load:
    • Support of 1200XL F1-F4 functions (dormant in OS code): on-the-fly ANTIC on/off for 30% boost of CPU time, International Character set ON/OFF, key-click ON/OFF, and HELP key for A800-i.
    • Avery's 2K Floating-Point Package, from Altirra OS, which runs at 2.2x-to-4x speed, and provides SUBSTANTIALLY HIGHER rounding precision and integrity than Newell's 2K package (passing ALL of AcidOS FPP tests).
    • OS load is signed with correct checksums for LOW and HIGH rom sections (8K+8K). It will pass built-in and external checksum tests.

Attached is 180K image with OS ROM image (16k) and documented source code. It is on its fifth iteration of coding and testing, good enough for a try on your A800-i, as well under ALTIRRA by using "attach Secondary Cartridge / RIGHT" feature. You can ALSO try it on XL based machines, as long as you manually join UNALTERED 8K-left and 8K-right images as a single 16K ROM image.

 

Attached File  SDX-Scratchpad-II.atr   179.64KB   30 downloads

 

Enjoy!


A800i (Incognito): Bringing back the RIGHT-Cart port...

Sat Dec 1, 2018 11:52 AM

...Let's face it: two cart ports is better than one, four joystick ports are better than two, five (5) motherboard slots are better than NONE... and with Incognito, yes, almost everything is better on the A800 than anything out-there...

 

...BUT, as you may contemplate all this A800 goodness, there's unfortunately a catch... In fact, there is a price to pay when upgrading to Incognito, as you may later understand.  Once everything is said and done, your RIGHT-Cart port (CartB) will become unusable... sort of an engine that somehow manages to work with one cylinder while the other is pretty much dead...

 

Well, no more! Introducing OS-XL load with "rC" (right-Cart) extensions, so you can bring back to life that dormant right-port and boot your favorite right-carts reliably, and in a plug-and-play basis!

 

Attached File  A800-rc_OS_Extensions-1.jpg   202.72KB   22 downloads

Attached File  A800-rc_OS_Extensions-2.jpg   192.08KB   22 downloads

 

 

 

 

plus some critical improvements and optimizations NOT present on native OS-b


Got the right MONKEY!

Fri Nov 16, 2018 3:37 PM

It is the second one....

...About to fire up the right-port of my A800i for the FIRST time since leaving factory, 35 years ago on 4 / 83...

Attached File  EEC3E6D5-6579-461D-8AF8-23669A192E06.jpeg   1.65MB   27 downloads

If it boots, I will be testing the guts out of it, including booting it under XL OS (Incognito) but with <= 8K left cart space (not a prepackaged 16Kbyte image)

Wish me luck! 8-)))

Optimus Prime (Transformers)... on Atari 800/XL...

Mon Nov 12, 2018 6:51 PM

Can it be done?

I only see a few colors and mostly gray-shadows.... Would LOVE to see it when booting the 800 / Incognito before getting to JFC BIOS.... (Already on my Z840... :-)

what do you guys think?

Attached File  4AA99824-6E41-461A-A00E-7FA329B11225.jpeg   381.21KB   23 downloads