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Imlac: Add support for Alpha display processor.

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This commit is contained in:
Lars Brinkhoff
2025-06-01 08:15:24 +02:00
committed by Mark Pizzolato
parent 02e63a1f97
commit fd60c6b0f7
1 changed files with 22 additions and 2 deletions
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24
imlac/imlac_dp.c
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@@ -29,6 +29,9 @@
/* Debug */
#define DBG 0001
/* Alpha display processor */
#define DP_ALPHA 0001
static t_addr DPC;
static t_addr DT[8];
static uint16 SP = 0;
@@ -77,13 +80,21 @@ static REG dp_reg[] = {
{ NULL }
};
static MTAB dp_mod[] = {
{ DP_ALPHA, DP_ALPHA, "Alpha machine", "ALPHA",
NULL, NULL, NULL, "Enables Alpha display processor" },
{ DP_ALPHA, 0, "Graphics machine", "ALPHA",
NULL, NULL, NULL, "Disables Alpha display processor" },
{ 0 }
};
static DEBTAB dp_deb[] = {
{ "DBG", DBG },
{ NULL, 0 }
};
DEVICE dp_dev = {
"DP", &dp_unit, dp_reg, NULL,
"DP", &dp_unit, dp_reg, dp_mod,
1, 8, 16, 1, 8, 16,
NULL, NULL, dp_reset,
NULL, NULL, NULL, &dp_imdev, DEV_DEBUG, 0, dp_deb,
@@ -168,12 +179,18 @@ dp_iot (uint16 insn, uint16 AC)
static uint16 deflect (uint16 msb, uint16 lsb)
{
return (msb << 5) + lsb;
if (dp_unit.flags & DP_ALPHA)
return 18*msb + lsb;
else
return (msb << 5) + lsb;
}
static void increment (uint16 *msb, uint16 *lsb, uint16 x)
{
*lsb += SCALE * x;
if (dp_unit.flags & DP_ALPHA)
return;
*msb += *lsb >> 5;
*lsb &= 037;
}
@@ -181,6 +198,9 @@ static void increment (uint16 *msb, uint16 *lsb, uint16 x)
static void decrement (uint16 *msb, uint16 *lsb, uint16 x)
{
*lsb -= SCALE * x;
if (dp_unit.flags & DP_ALPHA)
return;
*msb += ((int16)*lsb) >> 5;
*lsb &= 037;
}