VOGONS


First post, by Ozzuneoj

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I'm sure the number of people who still have these is getting pretty low, but I have had mine for 20 years and I am just now reading about this...

https://consolemods.org/wiki/CRT:Diamondtron_ … Unlocking_Guide

I will just quote the page here for posterity:

Diamondtron SB VSync & HSync Unlocking Guide Overclocking Tutorial […]
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Diamondtron SB VSync & HSync Unlocking Guide
Overclocking Tutorial

Diamondtron HSync & VSync Unlocking Tutorial (NOTE: Only works on 22" SB monitors):

Turn off the monitor.
Turn on the monitor while holding the EXIT button until you see a raster image then release and press EXIT again and you will see the FACT DATA menu.
Press the (-) button once to set the data value to 255 then press the (+) button to set the data value to 5 then press the SELECT button.
Navigate to the right in the OSD menu until you find the FACT DATA menu again.
Press the (+) button until the DATA value is set to 99 then press the SELECT button.
Press either the (◀) or (▶) buttons and you will be introduced to the FACT DATA-E2P menu.
Cycle through ADDR to change DATA values:
Change DATA Decimal in ADDR 004 to adjust the HSync Minimum +1 (31 is 30KHz)
Change DATA Decimal in ADDR 005 to adjust the HSync Maximum +1 (141 is 140KHz)
Change DATA Decimal in ADDR 006 to adjust the VSync Minimum +1 (49 is 48Hz)
Change DATA Decimal in ADDR 007 to adjust the VSync Maximum +1 (161 is 160Hz)
Press the EXIT button after each ADDR modification to save each address value then enter the FACT DATA-E2P menu again to change other ADDR values.
Exit the OSD.

Notes

This tutorial only applies for 22" Diamondtron SB monitors (and their rebadges) such as the 230SB and 2070SB.

The maximum known limit for the VSync and HSync are 254Hz and 152Khz respectively.

This tutorial does not need any additional equipment unlike Sony's WinDAS.

On my HP P1230 (rebadged Diamond Pro 2070SB) I was able to access this menu easily using these instructions. On mine, ADDR 004 (Hsync Minimum) is set to 29, which would apparently be 28Khz? Seems like an odd choice, but that's what it is.

I am able to change the value, but... I don't have the nerve to save it. I've had this thing forever and it works perfectly. It is basically the holy grail of 4:3 displays aside from its size and weight. To say that I'd be upset if I broke it would be an understatement.

Has anyone ever used this method to successfully get these monitors working with 15khz signals? What would be the reasoning behind not allowing these signals in the first place? Surely there has to be some downside to having this setting that low?

Now for some blitting from the back buffer.

Reply 1 of 5, by BitWrangler

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If you have your brightness maxed it will die in 2005 vs lasting until 2008. Usually it's higher frequency which blows the electronics, but the phosphor might burn a tad quicker with longer times per line so keep brightness down.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 2 of 5, by Ozzuneoj

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BitWrangler wrote on 2026-01-11, 04:31:

If you have your brightness maxed it will die in 2005 vs lasting until 2008. Usually it's higher frequency which blows the electronics, but the phosphor might burn a tad quicker with longer times per line so keep brightness down.

2005 is when I bought it... I'm not sure I follow. 🤣

I will do a bit more research on this before I start using it at 15khz. I have a feeling it would work fine, but I do have to wonder why they would prevent it from running at those resolutions if it is capable.

Now for some blitting from the back buffer.

Reply 3 of 5, by maxtherabbit

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do you have any evidence that it will actually sync down to 15kHz? or are you basing all this on the fact the minimum hsync freq is adjustable?

"adjustable" still implies that the range of adjustment is finite,there is a long way from 15 to 29

Reply 4 of 5, by BitWrangler

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Ozzuneoj wrote on 2026-01-19, 04:50:
BitWrangler wrote on 2026-01-11, 04:31:

If you have your brightness maxed it will die in 2005 vs lasting until 2008. Usually it's higher frequency which blows the electronics, but the phosphor might burn a tad quicker with longer times per line so keep brightness down.

2005 is when I bought it... I'm not sure I follow. 🤣

I will do a bit more research on this before I start using it at 15khz. I have a feeling it would work fine, but I do have to wonder why they would prevent it from running at those resolutions if it is capable.

I was pitching it 3 years from intro date I think. What I was trying to say is that if you ran it lowest frequency max brightness for 3 years as a daily driver, on for large chunk of the day, it might be getting burned and dim in 3 years. Official modes are probably optimized for their beam output to avoid that.

Anyway, the takeaway is that it's slightly bad for the monitor maybe, but you'd have to do a whole lot of slightly to age it more rapidly than you'd notice vs using it at desktop res.

Unicorn herding operations are proceeding, but all the totes of hens teeth and barrels of rocking horse poop give them plenty of hiding spots.

Reply 5 of 5, by Ozzuneoj

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maxtherabbit wrote on 2026-01-19, 13:35:

do you have any evidence that it will actually sync down to 15kHz? or are you basing all this on the fact the minimum hsync freq is adjustable?

"adjustable" still implies that the range of adjustment is finite,there is a long way from 15 to 29

No, I don't. In fact, yesterday I asked over at the crtgaming subreddit and after a rather confusing discussion where I learned some things I was wrong about and others kept misunderstanding what I was trying to do, it seems like it is probably not worth trying to do this, even if there was a way to make it work.

I somehow never realized that anything displayed on a VGA monitor that is running below standard VGA resolutions (640x480@60, 640x400@70, etc.) is scan-doubled by the VGA card to a VGA resolution to meet the 31.5kHz minimum requirement. So, what I thought was excellent picture quality at 320x200 on a big huge CRT is actually a 640x480@60Hz signal after being scan-doubled by my VGA card. I am told that if I were to see a non scan-doubled 320x200 image on this monitor the scan lines would be so thick it would look awful. This makes sense to me after understanding it better, and it also makes sense why the manufacturer would not allow this even if it doesn't break anything.

Also, someone else said they tried lowering the limits on a 2070SB and it didn't work. They were using what he described as a MiSTer FPGA RGBHV setup to output 15.7kHz horizontal and 59.8Hz vertical and the monitor said "out of range". So, I guess the consolemods.org page is intended to be used only to increase the limits to achieve higher refresh rates for various purposes. Lowering it wouldn't be that useful if 15kHz isn't achievable.

Now for some blitting from the back buffer.