marty1@houem.UUCP (M.BRILLIANT) (11/12/85)
As long as sob@neuro1.UUCP (Stan Barber) has replied on the net to my question about how to access the special features of the Model 4 when I only have a cassette system, let me continue: Stan says "... you can push info out to certain ports to make things happen.... but it is hard to use 64K of ram that is empty. Once you do the ROM swapout, there is no way to load the ram with anything.... You cannot use the 4 in III mode with the 80x24 screen without a special driver to cause all the video mapping to happen right.... Sorry this is such a downer." OK, no problem! I just want 80x24 for my terminal emulator. It has its own screen driver, it uses ports for RS-232, and I can copy a keyboard driver. The Model III screen and keyboard maps are in the part of the address space that goes away in Model 4 mode, so I have to know what to do instead. But I have the source for the terminal program. I can hack what I need, load it from cassette in Model III mode, let it swap into Model 4 mode, and run! So, I'm still asking Stan or anybody else: what info goes through what ports to get into, use, and get back from Model 4 mode? M. B. Brilliant houem!marty1 39 McCampbell Road Holmdel, NJ 07733 (201)-946-8147 AT&T-BL Holmdel, NJ (201)-949-1858
sob@neuro1.UUCP (Stan Barber) (11/15/85)
Here is a list of interesting ports for the Model 4. PORT 84H Bit 0 and 1 control the enable state of the Model III ROMS and the Video and keyboard mapping swapout. The following table illustrates this. BITS MODEL III ROMS ENABLED VIDEO/KEYBOARD STATUS 1 0 0 0 YES MODEL III MODE 0 1 NO MODEL III MODE 1 0 NO MODEL IV MODE (IN) 1 1 NO MODEL IV MODE (OUT) Bit 2 controls the format of the display.... 0 = 64X16, 1 = 80X24 Bit 3 when on means use reverse video Bits 4 5 and 6 control RAM bank select accoding to this table. BITS Lower 32K RAM Upper 32K RAM 6 5 4 0 0 0 Bank 0 Bank 1 0 1 0 Bank 0 Bank 2 0 1 1 Bank 0 Bank 3 1 1 0 Bank 2 Bank 1 1 1 1 Bank 3 Bank 1 Bit 7 controls what page to map the 64x16 screen into: 0 = page 0, 1=page 1 ports 88-8BH are ports on the CRT controller, but I don't know how they work. I can tell you that the CRT controller is a 68054. If you get more info here, please forward it. 90H allows you to sound the sound board. Hope this helps. Sorry to not be so helpful the last time. -- Stan uucp:{ihnp4!shell,rice}!neuro1!sob Opinions expressed Olan ARPA:sob@rice.arpa here are ONLY mine & Barber CIS:71565,623 BBS:(713)660-9262 noone else's.
uhclem@trsvax (11/15/85)
<I'm dreaming of a fixed notes handler, just like the ones I used to know....> How to set your Model 4 screen to 80x24 or 40x24 while staying in Model III mode. This is pretty easy. There is a port called OPREG$ (0x84) which controls the memory mapping and the CRTC-program select. It looks liks this: B7 B6 B5 B4 B3 B2 B1 B0 Page Fix Memory Memory Invert 80/64 Select Select Upper (0) Bit 1 Bit 0 Video Bit 1 Bit 0 Memory (Alt Set Select) Bit 2 controls if the CRTC is programmed for 80x24/40x24 or 64x16/32x16. The half-width adjustment is in port 0xEC (MODOUT), bit 2 (MODSEL). Bits 1 & 0 of OPREG$ decide what memory map to use. Since you want to stay in Model III mode, these bits should remain 0. This keeps the ROMs selected, and places the keyboard at 0x3800 and the video at 0x3C00. The Page bit (Bit 7) selects which 1K of the 2K video RAM is addressable at 0x3C00. It does not affect which page is shown on the screen in any mode. So what you get to do is write code to break your screen requests up and turn that bit on if you want the upper 1K and off if you want the lower 1K. OPREG$ is unknown to the Model III ROM and operating systems, so you will need to keep a copy of its contents in RAM somewhere as it is a write-only port. MODOUT is known, and Model III systems maintain a copy of it at 0x4210. So if you modify this port, be sure to read the copy at that address, and/or bits in it, store it back, then write to the port. (By the way, Bits 6-4 control banking when you have 128K.) All of the above information can be found in the Model 4/4P Technical Reference Manual 26-2110, and some of it was in Model III/4 Cassette BASIC Reference Manual or something like that. (Should have come with your 16K machine.) <This information is provided by an individual and is not nor should be construed as being provided by Radio Shack or Tandy Corp. Radio Shack/Tandy Corp has no obligation to support the information provided in any way. I mean, they didn't even show the Model 4D computer at the Annual stockholders meeting! And it was only 16% of Tandy computer sales (According to the annual report, page 16)! Gee Whiz!> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> "If you took the bugs out it wouldn't be crashy, would it?!?"
marty1@houem.UUCP (M.BRILLIANT) (11/21/85)
Thank you, Uh Clem (Frank Durda), and you too, SOB (Stan Barber), for the Model 4 port info. Checking it out in BASIC was fun; implementing it in ASM will be boring but useful. I got everything but sound. "OUT 132,4" puts up an 80x24 screen (at reduced brightness), with garbage in the bottom half and the lines out of alignment. "OUT 132,132" writes on the bottom half (but the last line is out of range of the screen). All I need (after installing an RS-232 interface) is a few obvious but messy fixes in my terminal program. "OUT 132,8" gets back to 64x16 with reverse video capability. After "PRINT CHR$(21)" or a POKE to 16420 (to turn off space compression), setting bit 7 gives ASCII characters in reverse video. Now the same characters that control underline mode on the printer (DMP-100) can be used for "standout mode" on the terminal. And a reverse-video cursor might be better than that blinkin' blinking cursor. Predictably, changing bit 0 or 1 in an OUT to 132 disables the machine until RESET is pushed, since the ROM goes away. Is there a noise-maker in the Model 4? I tried "OUT 144,everything" following Stan's suggestion that "90H allows you to sound the sound board" but got no sound. Am I missing something? I'd like to have an audible bell instead of the visible flash I now have. None of this is in the Model III/4 Cassette (whatever-title) Operation and BASIC Manual. The POKE and OUT for double-speed are in there, but RAM locations and ports are not mentioned for things you control by sending characters to the screen. M. B. Brilliant houem!marty1 39 McCampbell Road Holmdel, NJ 07733 (201)-946-8147 AT&T-BL Holmdel, NJ (201)-949-1858
uhclem@trsvax (11/27/85)
<"What do you mean 'It's in Reserved for future use phase'? Oh, its SCSI."> >"OUT 132,4" puts up an 80x24 screen (at reduced brightness), with That is right. I take it you have one of the older model units, and when you changed the screen clocking to the higher rate, the RFI torroids clip the white signal more obviously. If this bothers you, you can fix it real fast by pulling these out, but beware: on some units you will start picking up herringbone patterns and other harmonic crud in your video. In the later units they fixed this, and there may be a TCO available to cover it. Check with your local Service shop. >garbage in the bottom half and the lines out of alignment. "OUT Also right. The old Model IV ROM only cleared the 1K that was used in Model III mode, and it was the responsibility of any Model 4 operating system to clear the other half. You are just seeing uninitialized video RAM. As to the alignment, the Model IV ROM thinks that every 64th byte is the start of a new line, not every 80th, so things do get messed up it you try to use the ROM video drivers in 80 column mode. >Is there a noise-maker in the Model 4? I tried "OUT 144,everything" The port that I gave you is correct, but it finally registered that you have a diskless system. Look at the back (not the bottom) and see if the RS-232 port comes out of the machine at the seam between the top and bottom of the machine. If it is not there, then look underneath and see if it is in the second row, center hole on the bottom. If the RS-232 port is on the bottom and the machine has no disk drives, then it will not have a bell. It was decided (not by me, so no flames please) that if the machine could not run Model IV software (no drives), and no Model III software knew about the bell, then leaving that part off would be a nice way to cost-reduce the drive-less unit. If the RS-232 port comes out the back, then you get one no matter what, since the speaker is now built onto the motherboard. (The sound stuff gets added with the first floppy drive on the older units.) The schematic for the sound board (for machines with RS-232 port coming out the bottom) is on Page 22 of the Model 4 Technical Reference and is real big: |:(?) 4 +-----------------------------+--- +----O----+ | ^+5 D0 2| P | +--------------------+ 3>--------------|D U1 | | R1 1.8K / BLK | 74LS74 | +--\/\/\/---+ ^/ E SEN 3| | | / \ Q1=2N3906 1>--------------| ~Q|------\/\/\/---+---B( Q1 ) WHT | C |6 R2 3.6K \ /\C +----O----+ -- \__/\/\/\/--->QMB6<--+ |1 R3 120 OHM | | VCC (14)=+5 GND 2>----+---+5---------+ VDD (7)=GND | QMB6 is one of those piezo-speakers --- C1 .1uf without the tone generation circuitry. --- Don't use a Sonalert as you will always get | the same pitch. 4>----+---GND So you can build one if you find you don't have, or you might order a finished one from National Parts. With that part-count, it can't be too expensive. <This information is provided by an individual and is not nor should be construed as being provided by Radio Shack or Tandy Corp. Radio Shack/Tandy Corp has no obligation to support the information provided in any way. It is advised that you not place any hands or fingers in the disposer unit while it is in operation.> "Thank you, Uh Clem." Frank Durda IV @ <trsvax!uhclem> "The crime of copy-protecting bears bitter customers. The Lawyer knows."(tm)
root@techsup (11/28/85)
/* Written 9:31 am Nov 21, 1985 by houem.UUC!marty1 in techsup:net.micro.trs- */ Thank you, Uh Clem (Frank Durda), and you too, SOB (Stan Barber), for the Model 4 port info. Checking it out in BASIC was fun; implementing it in ASM will be boring but useful. I got everything but sound. ... 18 minutes of silence accidently deleted..... Is there a noise-maker in the Model 4? I tried "OUT 144,everything" following Stan's suggestion that "90H allows you to sound the sound board" but got no sound. Am I missing something? I'd like to have an audible bell instead of the visible flash I now have. None of this is in the Model III/4 Cassette (whatever-title) Operation and BASIC Manual. The POKE and OUT for double-speed are in there, but RAM locations and ports are not mentioned for things you control by sending characters to the screen. M. B. Brilliant houem!marty1 39 McCampbell Road Holmdel, NJ 07733 (201)-946-8147 AT&T-BL Holmdel, NJ (201)-949-1858 /* End of text from techsup:net.micro.trs- */ ****** If you have an early cassette model 4, the buzzer was not included. It came with the disk upgrade. ******