ZX Ferrum #00
09 января 2004 |
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Iron - scheme virtaulnogo ROM.
Virtual ROM (C) Demon / DPC One day, after the installation on his pentagon new firmware (NeOS v1.00, Gluk Reset Service v5.3, TrDos v5.13f), I found that the BASIC command PRINT 2 ^ 2 gives unexpected Results (something like 0. 8232839109-e10). Down and Out the trouble started as they say, further studies have shown that the sign of the copyright deprived the bottom line in the test firmware NeOS Notdetectable Notdetectable and besides the same version is clearly not 1. 00, many things did not work. But most of all I killed that does not work is my favorite igruha Terminator 2, digging in the code, I found the binding to interrupt Basic128, but since there NeOS or Service is advancing bummer. At that time there was one way to flash the ROM, but this time we have turned down the Spectrum in the same town (and I Speck came in 1999) and people through which I pierced ROM is not enough that struck down with Speck, thallium and generally somewhere ejected. But in some a newspaper I read an article that mentions virtual ROM where the real ROM is replaced with a memory page, but not of the arrangement, and had to think for yourself. I do not know how to look at the scheme of guy, but I got this: TM2 KP12 S1 ON 1oR May 2 S1 0v D DD61 / January 14 S0 YA 7 DD18 / 5 C OFF 4oS o6 0v 1 SA 6 A0 0v 5 A1 LE1 / 1 4 A2 3 A3 KP11 / DOSEN 3 A0 4 DD61 / 3 ROM2 6 A1 7 DD61 / 6 A2 A3 A15 2 B0 A16 5 B1 apply for a B2 DD50 / 1 B3 1 'S DD50 / 1 0v 15 OE LI1 LL1 1 DD51 / 4 DD51 / 4 Figure 1. The scheme of the virtual memory (the Pentagon) Signal LE1 / 1 memory expansion scheme the Pentagon and the Leningrad at 1mb Simm (was in some of the rooms DejaVu), ie, the multiplexer KP12 placed in the gap providing a signal bit at sample of addresses is less than # C000. Firmware loaded on the page # 31 - basic128, # 32 - dos, # 33 - basic48. When it all worked, I was very pleased, began to jump, clap (just kidding, it looked the part much more fun;)) and thought it would be nice to write a prog that would load the firmware. Well ... Well I did and wrote. It is in the annex to hrip archive there and firmware, which I have currently there and that I collect, so that if someone is flashing, that is not me, then send I will be glad. While the scheme is only available for the Pentagon. For all questions, please contact the publisher.
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