From 3e7f8a18de884e4ffe7ed9962b34442a4960017a Mon Sep 17 00:00:00 2001 From: OBattler Date: Tue, 1 Apr 2025 09:18:12 +0200 Subject: [PATCH] FDC: Initialize DRVRATE to 1 on the OKI IF386AX so that 1.25 MB floppies can be read on a 3.5" 3-mode drive. --- src/floppy/fdc.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/src/floppy/fdc.c b/src/floppy/fdc.c index 51c3aa24a..6ffa47f29 100644 --- a/src/floppy/fdc.c +++ b/src/floppy/fdc.c @@ -2268,10 +2268,21 @@ fdc_reset(void *priv) fdc_update_rwc(fdc, 1, default_rwc); fdc_update_rwc(fdc, 2, default_rwc); fdc_update_rwc(fdc, 3, default_rwc); - fdc_update_drvrate(fdc, 0, 0); - fdc_update_drvrate(fdc, 1, 0); - fdc_update_drvrate(fdc, 2, 0); - fdc_update_drvrate(fdc, 3, 0); + /* + The OKI IF386SX natively supports the Japanese 1.25 MB floppy format, + since it can read such images just fine, it also attempts to use data + rate 01 on a 3.5" MB drive (which is the only kind it can physically + take, anyway), and rate 01 on a 3.5" MB drive is usually used by 3-mode + drives to switch to 360 RPM. Hence why I'm switching DRVDEN to 1, so + rate 01 becomes 500 kbps, so on a 3-mode 3.5" drive, 1.25 MB floppies + can be read. The side effect is that to read 5.25" 360k drives, you + need to use a dual-RPM 5.25" drive - but hey, that finally gets those + drives some usage as well. + */ + fdc_update_drvrate(fdc, 0, !strcmp(machine_get_internal_name(), "if386sx")); + fdc_update_drvrate(fdc, 1, !strcmp(machine_get_internal_name(), "if386sx")); + fdc_update_drvrate(fdc, 2, !strcmp(machine_get_internal_name(), "if386sx")); + fdc_update_drvrate(fdc, 3, !strcmp(machine_get_internal_name(), "if386sx")); fdc_update_drv2en(fdc, 1); fdc_update_rates(fdc);