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So now resetting the ports before jumping:Code: [Select]sub_7f00: ; From bootloader br !llab_7fdb ;7f00 9b db 7f ; Go to failsafe checklab_7fdb: ; Failsafe check mov pm7,#0xf0 ;7fdb 13 27 f0 ; Set P7.7-4 as input, P7.3-0 as output mov pu7,#0xf0 ;7fde 13 37 f0 ; Enable P7.7-4 pullups mov p7,#0x00 ;7fe1 11 07 00 ; P7.3-0 outputs low movw ax,#0x0100 ;7fe4 10 00 01 ; Much smaller delaylab_7fe7: subw ax,#0x0001 ;7fe7 da 01 00 bnz lab_7fe7 ;7fea bd fb mov a,p7 ;7fec f0 07 ; Move P7 value into A mov pm7,#0xff ;7fee 13 27 ff ; Clear port config mov pu7,#0x00 ;7ff1 13 37 00 bt a.7,lab_7ff8 ;7ff4 31 7e 01 ; test A, bit 7 ret ;7ff7 af ; Return (Button pressed)lab_7ff8: br !lab_3015 ;7ff8 9b 15 30 ; Enter app (Not pressed)
sub_7f00: ; From bootloader br !llab_7fdb ;7f00 9b db 7f ; Go to failsafe checklab_7fdb: ; Failsafe check mov pm7,#0xf0 ;7fdb 13 27 f0 ; Set P7.7-4 as input, P7.3-0 as output mov pu7,#0xf0 ;7fde 13 37 f0 ; Enable P7.7-4 pullups mov p7,#0x00 ;7fe1 11 07 00 ; P7.3-0 outputs low movw ax,#0x0100 ;7fe4 10 00 01 ; Much smaller delaylab_7fe7: subw ax,#0x0001 ;7fe7 da 01 00 bnz lab_7fe7 ;7fea bd fb mov a,p7 ;7fec f0 07 ; Move P7 value into A mov pm7,#0xff ;7fee 13 27 ff ; Clear port config mov pu7,#0x00 ;7ff1 13 37 00 bt a.7,lab_7ff8 ;7ff4 31 7e 01 ; test A, bit 7 ret ;7ff7 af ; Return (Button pressed)lab_7ff8: br !lab_3015 ;7ff8 9b 15 30 ; Enter app (Not pressed)
IMHO relying in the forum storage is the least reliable way, but attached anyways .
So there is NEC uPD78F0547 inside. My Fluke 189 uses Sharp SM6004 chip. No docs, no tools, etc. What was the reason for widely using a Japanese MCUs in the DMMs of the US brands? If there was a shortage of the domestic MCU designs back at that time?
Quote from: Njk on February 24, 2024, 06:46:01 pmSo there is NEC uPD78F0547 inside. My Fluke 189 uses Sharp SM6004 chip. No docs, no tools, etc. What was the reason for widely using a Japanese MCUs in the DMMs of the US brands? If there was a shortage of the domestic MCU designs back at that time?Maybe those design teams are in Asia, and they naturally gravitate to home-grown mcu's.US based design teams are perhaps more focussed on bench / high-end gear, where "western" mcu's are common.Just guessing. Maybe just cost driven.
How to replace the Agilent / Keysight OLED display for just $10! - Buy the display: Aliexpress (Or search for "SSD1309 8080"). (Attachment Link) - You might need to install the Prolific drivers. If getting code 10, install the attached drivers.- Make sure Windows is using them: Open the Device Manager, check those under USB devices/USB serial port and COM ports/USB serial port, replace driver if needed.- Don't attempt loading a firmware from another model, it'll brick the device! (Not irreversible, see Recovering section below)Agilent / Keysight U1273A / U1273AX If your device has firmware version v4.xx it will work straight away, no firmware modification is required! - Confirmed working! - Download and extract U1273A(X)_V303_mod.zip. - Run the updater. - Original installers from Keysight: U1273A, U1273AX . Must be v3.01, newer version will check the current firmware and block the update if already in the latest version! Just change the firmware name to U1273A(X)_V301.AG. (A or AX).Agilent / Keysight U1253A - Confirmed working! - Download and unpack Agilent U1253A Firmware Update V120_mod.zip. - Run the updater.Agilent / Keysight U1253B - Same mod as 1253A, so it should work. - Download and extract U1253B_V304_1123a_mod.zip. - Run the updater.Reverse enginnering detailsAll the bits & low-level details can be found few posts below.RecoveryIf something goes wrong, it's pretty easy to recover using a usb-serial converter, read the messages starting here.