August 2017 - vcf-midatlantic

Museum is open despite street work at Infoage in August
by Jeffrey Brace 02 Aug '17

02 Aug '17

Despite the sewer pipe operation to replace the pipes on Marconi road, InfoAge is open. Our museum is open too. I will be here Wednesday Aug. 2 & 9, and probably for the rest of the Wednesdays in August. We are usually not open on Wednesdays, but I'm a school teacher, so I can be docent in the summer on Wednesdays. Anyway, be aware that the front entrance is open today. Next Wednesday you may have to use the back entrance. As the road work goes down the road you may have to use an alternate route to get to InfoAge on weekdays. I believe that this would be via Brighton Ave and Watson Road to go through the back way. Weekends should be fine. They don't work on the road on the weekends. -- ======================================================== Jeff Brace ========================================================

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Book review
by Evan Koblentz 02 Aug '17

02 Aug '17

"IEEE Annals of the History of Computing" is the top academic journal covering computer history. The current issue has a review of my book, "Abacus to smartphone: The evolution of mobile and portable computers". The reviewer was fair in observing what I did well and what I could have done better. She concluded that it's an "accessible read ... recommended for historians of all stripes or those with an interest in wide-ranging narratives of computer technology". That was exactly my goal when I started researching it more than a decade ago: to make the book accessible to the public yet also credible to professional historians. Goal achieved! Happy camper tonight. I emailed the journal editor to ask about their rules for quoting/reprinting -- I do not intend to break them. Nobody should take it upon themselves to host the PDF. IEEE members can read it here: https://www.computer.org/…/an/2017/02/man2017020009-abs.html ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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Re: [vcf-midatlantic] assembler is tedious (was WooHoo!)
by Jeffrey Jonas 02 Aug '17

02 Aug '17

Not to fan the flames but I have experience and opinions on the subject: Glenn Roberts via vcf-midatlantic writes: >I hate to be the bearer of bad news but assembly language is probably >the most tedious of programming environments. VAXman: > That's not necessarily true. It depends upon the machine (CPU) > and its language (instructions, address modes, registers, conventions, etc.). Part of me wants to agree, having assembler programmed 8, 16, 32 bit machines. There's a deep satisfaction to optimizing a program with "green card" in hand (IBM 360 reference card - lists all instructions). But even I must concede that assembler programming the Z80 was dogmeat after having programmed IBM 360/370. Too few registers, weak instructions and other things that make assembler programmers happy. Even now, when considering microcontrollers, I look over the instruction set as some measure of goodness: is the architecture clean? Are the instructions flexible enough to do as much as possible in one cycle? But assembler programming is just the tip of the iceberg. There are programming "traditions" and conventions, particularly register usage, if you're to link to any libraries or supervisor calls. Assembler programmers depend a lot of macros and libraries to make their programming environment more pleasant. The joy of the IBM 1130 was seeing your program running on the front panel and understanding what it was doing on the lowest possible level! Lotsa libraries and shareware, even in the 70s. But that's all for CISC CPUs. RISC sapped out all the pleasure with too many details for humans to track: pipelining, delayed branch, instruction hazards, cache, etc. Concurrent Computer Corp converted from 360-like microcoded CPUs to the MIPS R3000. The internal courses were wonderful, covering all the aspects why RISC is the way to go, and all the trade-offs, particularly the need to rely on the compiler for optimization and bug fixes/workarounds. >Good assembly language programmers have libraries of frequently needed >routines (e.g. to print text or do = 16 bit manipulations). It helps a lot. The 68000 trainer I used for a lab course had a few functions in the ROM such as print character, print string. It sure accelerated my progress. But if there were no ROM, a simple workaround would've been to cut-and-paste just the functions I needed into the source file. Or learn the link-editor to link the main to libraries. > I/O routines, unless one is writing the I/O subsystem and device drivers, > should be part of the OS or, in lesser systems, ROM, Bios, etc. > Inventing the wheel everytime you want to roll is not very productive. Agreed. That's part of why 70s Development Boards were really USEFUL once ROMS/EPROMS were large enough to have some support. CP/M started the portable "BIOS" concept: a minimal set of foundation subroutines upon which everything else is built. I still marvel at how much functionality Woz squeezed into the Apple 1 with those TEENY ROMS (256 bytes?) -- jeff jonas

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GW-48T02-1 a Replacement for 48T02 RTC/NVRAM Batteries
by systems_glitch 01 Aug '17

01 Aug '17

All, I've got a pile of old Sun boxes I'm going through, dealing with dead NVRAMs of course. I ordered some ST 48T02 replacements from Mouser, only to find out they're not 100% compatible. So, since I was going to have to modify a whole bunch of old 48T02s, and there are space constraints on some of the systems, I designed a little module with a CR1225 and crystal to totally replace the CAPHAT on a 48T02. Here's the writeup: http://www.glitchwrks.com/2017/08/01/gw-48t02-1 I've got 100x on order, in panels of 10. If anyone is interested in some bare panels, assembled modules, or complete 48T02 replacements, let me know! I'll be doing other modules for the 48T08 and probably one to turn a DS12885 into a DS12887. Thanks, Jonathan

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Sym-1 craigslist
by william degnan 01 Aug '17

01 Aug '17

https://philadelphia.craigslist.org/sys/d/vintage-collectable-synertek/6228…

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LinApple
by Evan Koblentz 31 Jul '17

31 Jul '17

Anyone use LinApple? I'm using it on Linux Mint. It says to press F3 or F4 to load a disk image. But when I press either of those keys the program window closes. ________________________________ Evan Koblentz, director Vintage Computer Federation a 501(c)(3) educational non-profit evan(a)vcfed.org (646) 546-9999 www.vcfed.org facebook.com/vcfederation twitter.com/vcfederation instagram.com/vcfederation

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