44cc9f3f6d
Custom TTL design by Marvin Minsky. There are two displays: one raster scan for bitmapped characters, and another random scan for vector graphics. There is also a keyboard, and a UART for talking to a host computer. The computer is normally booted off a ROM which reads and starts a secondary loader from the UART. The loader is responsible for reading the payload, which comes in checksummed blocks. The LOAD command accepts files in same format.
115 lines
2.8 KiB
C
115 lines
2.8 KiB
C
/* tt2500.c: TT2500 display interface.
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Copyright (c) 2020, Lars Brinkhoff
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Permission is hereby granted, free of charge, to any person obtaining a
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copy of this software and associated documentation files (the "Software"),
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to deal in the Software without restriction, including without limitation
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the rights to use, copy, modify, merge, publish, distribute, sublicense,
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and/or sell copies of the Software, and to permit persons to whom the
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Software is furnished to do so, subject to the following conditions:
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The above copyright notice and this permission notice shall be included in
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all copies or substantial portions of the Software.
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THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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LARS BRINKHOFF BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
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IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
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CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
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Except as contained in this notice, the name of Lars Brinkhoff shall not be
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used in advertising or otherwise to promote the sale, use or other dealings
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in this Software without prior written authorization from Lars Brinkhoff
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*/
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#include "display.h"
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#include "tt2500.h"
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#if defined(__cplusplus)
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extern "C" {
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#endif
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int tt2500_init(void *dev, int debug)
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{
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return display_init (DIS_TT2500, 1, dev);
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}
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static void tt2500_point (int x, int y, int i)
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{
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if (i < 7)
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display_point (x, y, DISPLAY_INT_MAX*(7-i)/7, 0);
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}
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int tt2500_cycle(int us, int slowdown)
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{
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return display_age (us, slowdown);
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}
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#define ABS(_X) ((_X) >= 0 ? (_X) : -(_X))
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#define SIGN(_X) ((_X) >= 0 ? 1 : -1)
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static void
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xline (int x, int y, int x2, int dx, int dy, int i)
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{
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int ix = SIGN(dx);
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int iy = SIGN(dy);
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int ay;
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dx = ABS(dx);
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dy = ABS(dy);
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ay = dy/2;
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for (;;) {
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tt2500_point (x, y, i);
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if (x == x2)
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break;
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if (ay > 0) {
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y += iy;
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ay -= dx;
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}
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ay += dy;
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x += ix;
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}
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}
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static void
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yline (int x, int y, int y2, int dx, int dy, int i)
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{
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int ix = SIGN(dx);
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int iy = SIGN(dy);
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int ax;
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dx = ABS(dx);
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dy = ABS(dy);
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ax = dx/2;
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for (;;) {
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tt2500_point (x, y, i);
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if (y == y2)
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break;
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if (ax > 0) {
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x += ix;
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ax -= dy;
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}
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ax += dx;
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y += iy;
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}
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}
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void
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tt2500_line (int x1, int y1, int x2, int y2, int i)
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{
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int dx = x2 - x1;
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int dy = y2 - y1;
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if (ABS (dx) > ABS(dy))
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xline (x1, y1, x2, dx, dy, i);
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else
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yline (x1, y1, y2, dx, dy, i);
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}
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#if defined(__cplusplus)
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}
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#endif
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